Considerations for the
Visually Impaired Older Worker
Jan K. Connolly, O.T.R.ll. Vision Rehabilitation Specialist/Consultant Arlington, Massachusetts
Every year, skilled, experienced people in the work force lose their sight. Although vision impairment can date from birth or be due to subsequent illness or accident, in two-thirds of all instances it is related to aging. 1 The American Academy of Opthalmology reports that the prevalence of eye disease increases throughout life from 1 % of preschool children to 85 % of older adults. 2 Visual impairment represents the third most common limiting function among the aged3 and vision is among the first of the senses to weaken with age. 4 The incidence of visual impairment increases with age from 1 person per thousand under 45 years of age to 6 persons per thousand aged 4564, and to 44.5 persons per thousand aged 65 and 0lder.5 The population in the United States is aging. In about 40 years, almost one-third of the population will be age 65 or older. 4 This increase in the aging population, paired with the fact that age is the single most significant predictor of the prevalence of visual impairment, indicates that the population ofindividuals with visual impairment will continue to grow and that more visually impaired people will be in the work force. Less than one-third of working-age (18-64 years) visually impaired people are in the labor force (either working or actively seeking work), compared to almost three-fourths of the general population. 6 However, this does not distin-
guish between those who are congenitally or adventitiously visually impaired early in life and those who begin to lose their vision later in their working years. Underemployment is common for the blind and visually impaired population, though the reasons for this have not been identified. 7 People with vision loss are underrepresented in professional, managerial, and clerical positions and overrepresented in manual occupations. Although the research does not identify why this is so, the former set of occupations emphasize reading and tend to pay better. 6 In many cases, especially among those who begin to lose their vision later in their working careers, necessary accommodations which would permit them to continue to function in their current jobs are available and possible. Employers are more likely to accommodate a visually impaired person already employed and trained in his or her position when vision begins to faiU Often, only a small portion ofthe job, involving reading or detailed work, causes difficulty. The intent of this article is to focus on those individuals already in the work force who begin to experience vision loss later in their working years. What follows is a discussion of possible problems and solutions that may allow aging visually impaired workers to remain in their jobs. The focus for these individuals is on relearning and adapting tasks they have done all along rather than learning new and unfamiliar tasks. However, it should be understood that there is not always a solution for every individual and for every job task. In some cases it may be necessary to reassign isolated aspects of ajob WORK 1991; 2(1):19-28 Copyright © 1991 by Andover Medical Publishers, Inc.
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or to change pOSItlOns completely, but often this need not occur when problems are addressed individually with creativity and technology.
DEFINING THE POPULATION Several terms are used to describe the visually impaired population, including blind, legally blind, and visually impaired. Blindness is frequently used to describe the sight of any individual with limited vision, including those who are totally blind (no light perception). Fewer than 1 in 20 "blind" people have no light perception; almost all have usable residual vision. 8 Legal blindness is an arbitrary cut-off point in the continuum of visual impairment developed to determine eligibility for registration with state agencies serving the blind and visually impaired. These agencies exist in every state and provide many benefits and services to registered individuals. Legal blindness means that vision in the person's better seeing eye is worse than 20/200 with correction or the field of vision in the better seeing eye is no more than Table 1.
20° (normal is 180°). Eighty percent of those who are legally blind have usable vision, 1,3 and more than two-thirds are over age 55. 3 Impaired vision can refer to any degree of vision loss from minimal loss up to and including total blindness. For the purpose of this article, visual impairment will describe individuals whose vision loss in some way limits their functioning. It should be understood that these terms do not take into account how well individuals use their vision. Many individuals who are legally blind are able to function quite well in their environments. In fact, two individuals with the same visual disease and measurable degree of vision loss will often function very differently. Solutions or adaptations for problems caused by vision loss are highly individual.
NORMAL AGING OF THE VISUAL SYSTEM Normal changes in the aging visual system can lead to functional difficulties. 9 As one ages, visual acuity - the ability to read (or see) small
Considerations for the Effects of Normal Aging on Vision
Visual Effects of Normal Aging
Treatment
Decreased visual acuity
Appropriate eyeglass prescription Large print materials
Decreased accommodation (presbyopia)
Appropriate reading or bifocal prescription
Narrowing of visual fields
Education of worker Increased lighting and contrast, especially in areas of mobility
Diminished visual search
Train in organized scanning techniques
Decreased color discrimination in violet/ blue range
Avoid like colors in violet/blue range Educate worker on deficit
Increased glare sensitivity
Cover/eliminate glare sources Tinted lenses
Increased need for light
Supplemental lighting for near tasks Adequate, even ambient lighting
Slowed light/dark adaptation Increased figure-ground confusion/ visual clutter
Good lighting, especially in entranceways Solid colors for backgrounds Avoid busy patterns and prints for large areas Organization of work area/materials
Slower visual processing speed
Maximize visibility of objects, tasks and environment through all of the above techniques
Decreased confidence in performing visual tasks
Visually Impaired Older Workers
details - declines. 10 Visual acuity is best at age 18 and gradually declines until age 40, after which an even sharper decline occurs. II Accommodation, the ability of the eyes to focus on objects at varying distances, decreases with age. The ciliary muscle of the eye loses some of its tone and power to control lens thickness, resulting in decreased accommodation. 3 Beginning at age 40, it is increasingly difficult to focus on near objects. This condition is called presbyopia and is usually correctable with glasses. The pupils get smaller as one ages, allowing less light into the eye and requiring increased illumination. lo A 60-year-old retina receives approximately one-third the amount oflight as a 20-year-old retina. 12 Increased sensitivity to glare and longer light/dark adaptation time are also seen. Glare is caused by an object reflecting excessive light back into the eyes due to too much or the wrong kind of light. II Light/dark adaptation is the ability of the eyes to adjust to changes in lighting levels. It takes longer for the aging eye to adjust to abrupt changes in lighting levels, as may be encountered when entering a dark storeroom from a brightly lit work area. Visual search begins to diminish in the 50s, and visual field gradually narrows with age. IO •11 It is harder to see violet and blue due to yellowing of the lens. 13 Increased sensitivity to glare, increased need for light, and decreased color discrimination may all contribute to decreased contrast sensitivity. An aging person is less able to deal with visual clutter and figure-ground confusion. An object viewed against a "busy" background is harder to see. In addition, slower speed in visual processing and decreased confidence in performing visual tasks have been reported. 14 See Cullinan8 and Weale 3 for additional information on the underlying physiological processes of these functional results. The cumulative effects of the visual problems associated with aging hinder an individual's ability to perform visual tasks that were once done with ease. Solutions for these normal visual changes may be as simple as providing an appropriate reading or bifocal prescription,
21
increasing the amount oflight, color contrast, print size, and spatial organization, and minimizing glare and visual clutter (Table 1). Education of older employees and their employers should be emphasized in developing effective compensatory techniques and minimizing disability related to aging eyes. Increasing awareness of the normal effects of aging on vision, including when and why difficulties may be present (such as why one may see better at certain times of the day or why some tasks provide better contrast, and thus are more visible than others) is the first step toward developing effective strategies for dealing with these limitations.
COMMON EYE DISEASES ASSOCIATED WITH AGING The four most common eye diseases associated with aging include cataracts, macular degeneration, glaucoma, and visual complications from diabetes.
Cataracts A cataract is an opacity or clouding of the lens of the eye behind the pupil. As lens becomes cloudy, passage of light to the retina, where images are formed, is blocked. Development of a cataract can lead to degradation of images, glare disability, reduced acuity and contrast sensitivity, and impaired color perception. 9
Macular Degeneration Macular degeneration is caused by the deterioration of the light-sensitive cells and the pigment cells in the small center part of the retina (the macula), which is responsible for fine detailed vision and color vision. Initially, this may affect only one eye and not impair function, but the condition is progressive and eventually will affect both eyes. The rate of progression is highly variable among individuals. Functional manifestations include central distortions, decreased acuity, central scotomas (blind spots), increased sensitivity to glare, and reduced contrast sensitivity and color discrimination. 9
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Glaucoma Glaucoma occurs when the pressure inside the eyeball rises above normal and affects the blood supply to the retina and optic nerve; it is almost always caused by failure of the fluid inside the eye to drain adequately.15 Functional losses that occur with glaucoma include reduced visual function in dim light, reduced contrast sensitivity, glare disability, peripheral field loss, increased light/dark adaptation time, reduced color discrimination, decreased acuity, and central field loss.9
Diabetic Retinopathy Diabetic retinopathy is caused by the deterioration of the blood vessels feeding the retina at the back of the eye. Abnormal blood vessels grow and bleed into the vitreous, the clear gel filling the center of the eye that gives the eye its shape. When leaking blood or fluid damages or scars the retina, the image sent to the brain is blurred. Functional losses resulting from diabetic retinopathy include reduced contrast and visual acuity, glare disability, scotomas, field loss, and reduced light/dark adaptation abilities and color discrimination. 9 Individuals with disease-related visual impairment may require more involved solutions and adaptations to continue functioning on the job than individuals experiencing only the normal effects of aging. Interventions should include an eye examination by an opthalmologist to diagnose and provide medical intervention for the eye disease and a comprehensive functional vision evaluation by a vision rehabilitation service or low vision clinic to determine the amount of remaining functional vision; prescription of optical devices and training in their use, as well as other nonoptical devices and techniques, may also be indicated. An individual determined to be legally blind should register with the state agency serving the blind and visually impaired to be eligible for services provided by the agency, including rehabilitation' vocational counseling, and orientation and mobility training. Additional interventions should include employee/employer education, environmental and work task evaluation and adaptation (including enhanced lighting
and color contrast, glare control, visual skills training, organization of work area), and devices (including magnifiers, computer adaptations, and other sensory and technological devices) (Table 2). Thorough training in the use of all necessary devices and adaptations is crucial to the success of the rehabilitation process.
EVALUATION A comprehensive evaluation is necessary to identify the visual requirements of the job. Once tasks involving vision are identified, task analysis further isolates the specific visual components within each task that cause functional problems. It may also be necessary to assess the degree of flexibility in the worker's job responsibilities in case certain job tasks must be reassigned. The work environment must also be analyzed, including the individual's work station or desk area, areas of travel such as entranceways, hallways, stairs, and storage areas, and other areas such as bathrooms, conference rooms, and cafeteria. These areas should be assessed for lighting levels and color contrast. After evaluation, the specific aspects of the job and environment that present difficulties should be identified. It may then become apparent that relatively few tasks or isolated components of tasks need adaptation, rather than the entire job. When looking for reasonable and functional solutions, remember that each individual is unique and several devices and/or techniques may be tried before arriving at a solution acceptable to both worker and employer. Involving the employer in the rehabilitation process may help. The more the employer understands the worker's needs, the more open he or she may be in providing or allowing the necessary devices and adaptations.
THE REHABILITATION PROCESS Optical and N onoptical Devices There are four ways to enlarge an image on the retina: relative-size magnification, relative
Visually Impaired Older Workers
Table 2.
23
Considerations for the Effects of Visual Disease Associated with Aging
Effects of Disease on Vision
Treatment
Degradation of images
Enhanced lighting and color contrast
Increased glare sensitivity
Cover/eliminate glare source Tinted lenses
Decreased visual acuity
Optical devices CCTV, computer adaptations Large-print materials Enhanced lighting/color contrast Move closer to object of view
Decreased color discrimination especially in violet/blue range
Enhanced color contrastllighting Avoid like colors in violet/blue range Individual assessment to determine best color combinations for contrast
Central distortions/scotomas
Train in eccentric viewing Optical magnification CCTV, computer adaptations Large-print materials Enhanced lighting/contrast Move closer to object of view
Increased need for light
Supplemental lighting for near tasks Adequate, even ambient lighting Illuminated optical devices Carry flashlight or penlight
Visual field loss
Mobility training Training in systematic scanning techniques Keep travel routes free of clutter/obstacles Tinted lenses Good lighting, especially in entranceways Wait for eyes to adjust to abrupt changes in lighting before moving
Slowed light/dark adaptation
distance (approach) magnification, angular magnification, and projection magnification. 16 Relative size magnification involves making the object itselfbigger. The most common example of this is large print materials. Relative distance magnification is achieved by bringing the object closer to the eye, such as holding printed material up close or moving closer to the object of View.
Angular magnification involves the use of optical systems, including hand-held, stand, and spectacle-mounted magnifiers, and telescopic devices. Some of these are designed for near and intermediate visual tasks while others are designed for distance-viewing tasks and mobility. These optical systems should always be prescribed by a vision rehabilitation service to ensure that the most appropriate and functional
device is obtained. An individual may be prescribed several different optical devices for specific tasks. For this reason it is important that the worker, when evaluated for these devices, be specific about the tasks he or she must accomplish at work, at home, and in travel. These devices are designed either for monocular or binocular use. Hand-held magnifiers can be illuminated or nonilluminated, may fit in a pocket, or may be attached to a spring arm for hand-free use. Generally, the larger the lens, the weaker its power, so an individual in need of a strong magnification may be limited by smaller lens size and thus a smaller field of view. Hand-held magnifiers are generally used for relatively short-term near and intermediate tasks such as reading dials, controls, and labels, or referring
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WORK / FALL 1991
to papers during a meeting or conference. One must be trained which eye to use, how far to hold the lens from the eye and from the object, and how to coordinate movement ofthe magnifier to keep one's place on the page or object of View.
Stand magnifiers differ from hand-held magnifiers in that they are placed directly on the surface of the object of view and have a fixed focal distance. They are useful for longer term viewing of near and intermediate tasks since they need not be held at a precise working distance and are slid along the page or object of view. Stand magnifiers are also helpful for individuals with arthritis, tremors, or other physically limiting conditions that prevent them from holding and manipulating a hand-held magnifier. Stand magnifiers are available with or without illumination. As with hand-held magnifiers the stronger the power, the smaller the size of the lens. Techniques for use of stand magnifiers are similar to those for hand-held magnifiers. Microscopic lenses or spectacle-mounted magnifiers are essentially strong reading glasses. They are useful for longer term reading and leave both hands free to manipulate the reading material. However, the reading material must be held anywhere from 10 inches to less than 1 inch from the lens for the material to be in focus. Also, the field of view is limited: only one word, or even a portion of a word, may be visible at a time. The individual must learn which eye(s) to view with, how close to hold the reading material, and how to move the reading material across the line of vision to avoid constant refocusing and without losing his or her place on the page. Lighting is important when using spectacle-mounted, hand-held, or stand magnification. It is difficult to provide adequate direct light on the object being viewed, while maintaining the necessary working distance of the device, without causing glare. Telescopic devices are frequently prescribed for distance viewing, but are also made for intermediate distance and tabletop tasks. The telescope may be monocular or binocular, and can be hand-held or mounted in frames to
wear. Drawbacks of telescopes include limited field of view, the need to stand still and hold the telescope steady, difficulty in refocusing for objects at different distances, and locating the object to be viewed. Distance telescopes are used to view street and building signs, or people or visual demonstrations across a room. Telescopes designed for intermediate viewing may be used for assembly work (if done at a constant distance), writing, and other tabletop tasks. Projection magnification enlarges an image by projecting it onto a screen. The type of projection magnification most commonly used by the visually impaired is closed-circuit television (CCTV). This device uses a television screen with a camera mounted next to or under the screen, with a platform on which to place reading material underneath the camera. The image of the reading material is electronically enlarged on the screen. CCTV is expensive compared to other types of magnification, but is very useful. Unlike the other devices, CCTV can magnify images from 8-60 times. Until recently, CCTV was used mainly for reading and writing, but current developments include a lens that can focus on three-dimensional objects or detailed hand work required in some assembly work. The contrast and brightness of the image on the screen are adjustable, and one may choose either a positive (black print on a white background) or negative (white print on a black background) image. CCTVs are now available in color, which may be useful for working with color-coded circuit boards or color graphics. Aside from cost, the main drawback ofCCTV is that it is relatively stationary, although here, too, portable versions ofCCTV have been developed. Other projection magnifiers include slide and movie projectors. Most individuals will benefit from a combination of these four types of magnification. In addition to the many optical devices available, there is also a wide variety of nonoptical devices which can assist the visually impaired individual to function more effectively. Items such as writing guides - plastic templates that fit over a check or other frequently used form - allow one to write in the appropriate spaces and stay
Visually Impaired Older Workers
on the lines. Bold-lined paper is available, as are bold black felt-tip pens which may allow visually impaired individuals to read their own, as well as other's, writing. Large-print typewriters are also available, as are large-print telephone overlays for rotary and pushbutton phones, and large-print and memory phones. Special lighting is a non optical device which will be discussed in detail under the following section on environmental modifications. Bookstands are helpful for comfort and positioning, especially when used with a close-focusing magnifier, or when reading material must be held close to the viewer.
Sensory and Technological Devices Computer adaptations comprise the largest group of technological devices. The availability of computer adaptations has allowed many visually impaired individuals to remain in their jobs, and will continue to do so. Three basic types of computer adaptations are available: enlarged print, speech, and braille. Larger print can be obtained by using a larger monitor, a screen magnifier, a large-print software package that provides adjustable magnification or characters of graphics on the screen, and large-print printers. Speech-synthesizing components can read out instructions and text from the screen. Other devices allow the user to input braille and read back what is on the screen by braille output. Braille printers are also available. In addition to computer adaptations, there are now a number of other "talking" devices on the market. These include talking scales, cash registers, calculators, and digital tools for machinists and mechanical or industrial engineers.
Visual Skills Training For certain types of vision impairment, visual skills training such as scanning or eccentric viewing may help to maximize functional use of vision. Organized scanning involves moving the head or eyes back and forth to take in more of the environment. An individual with peripheral field restriction may need to scan by mov-
25
ing the head from side to side to see a whole room and avoid tripping over unseen furniture or equipment, to view an entire desktop area to locate an object, or to avoid knocking an unseen item off of the desk. An individual with macular degeneration and a central scotoma (blind spot) may need to learn eccentric viewing, the technique oflooking around the scotoma and utilizing the peripheral vision. Both of these techniques must be learned and usually require considerable training.
Environmental Modifications Illumination and Glare Control. Some degree oflight is necessary to see. Some tasks require more light than others, especialiy those involving fine detail such as reading or those with poor contrast or a high degree of visual clutter. 17 The normally aging eye requires three times more light than the eye of a young adult. 12 When visual disease is present, the need for light becomes even more crucial to functioning. Thus, the amount oflight needed by an aging person is dependent on three things: the presence of age-related visual changes, the presence of eye disease, and the task at hand. 17 In addition to the need for more light, an increased sensitivity to light may occur, resulting in glare. Glare decreases visibility of an object or area by decreasing its contrast against the background, making visual functioning more difficult. A common problem faced by the older visually impaired population is how to get enough light without causing glare. Three general areas should be considered when adapting lighting: work station or desk areas where close work is done, general room or ambient lighting, and areas of travel such as hallways and stairs. For close work, direct supplemental lighting is needed; in fact, the more detailed and fine the task, the greater the need for direct supplemental lighting. An adjustable gooseneck or flexible neck reading lamp is most often used for this purpose. To avoid glare and get the most light on the work, proper bulb wattage
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WORK/FALL 1991
and positioning are critical. A single reading light with a 60-watt bulb is often sufficient for reading and detail work if the light is placed at the correct angle and close enough to the work material. A high-watt bulb is not usually necessary and may generate too much heat when placed close to the work surface. A reading light with a white or silver lining reflects more light. Individuals performing detailed tasks away from a desk or stationary work area may find flashlights or penlights helpful. There should be sufficient ambient lighting when using a supplemental lamp for reading or using a computer screen, to avoid problems due to slower light/dark adaptation. If the surrounding environment is not adequately lit, momentary "blindness" may occur while the eyes adapt to extreme changes in lighting levels. Weale l2 states that if local illumination is raised, luminance of the area immediately surrounding the highly-illuminated work area should be raised to about one-third of that of the work area to eliminate apparent pools of darkness. 12 General ambient lighting should be constant, even, and uniform to avoid shadows or glare caused by bright spots. It is difficult to generalize about which type oflight is best. Many individuals with impaired vision prefer standard incandescent bulbs for close work and report that fluorescent lights are more visually fatiguing, possibly due to the flicker effect that fluorescent lighting can cause, while others prefer fluorescent lighting for close work. Fluorescent lighting can provide even lighting for general room illumination, but should be shaded or recessed to limit glare. Many visually impaired individuals use sunlight, .which can be a very good source of illumination when properly used. However, while some may prefer sunlight, it is not always available and provisions should be made for additional lighting on cloudy days or for nighttime work. When using sunlight for near work, the individual should sit with their back or side to the window. To minimize glare, sunlight should come from behind or over the shoulders. Bulbs, lampshades, and windows should be kept clean. A recent flyer sent out by the Boston
Edison Company states that dust can reduce light by as much as 15%. Also, worn out or flickering fluorescent bulbs should be replaced. Glare can be minimized by proper placement and positioning of lights and by covering any large shiny surfaces: highly polished floors can be covered with rugs or given a dull wax finish; shiny table tops can be covered with cloths; desk tops can be covered with a large desk blotter; and windows should have shades and (if possible) polarized glass. When adapting light to suit the visually impaired individual consider the following statement as a guideline: "Good sight needs good light; and good light is not only bright light but light tailored to the task and to the individual. "17 Color Contrast and Visual Clutter. Enhancing color contrast involves making an object more visible against its background. Even the complete absence of glare and the most appropriate lighting may do little to help a visually impaired person see an object if there is insufficient color contrast between it and its background. 18 For reading, print contrast is important. Poor-quality print, such as that from a dot matrix printer, newsprint, poor xerox copies, blueprints, or anything written in pencil (especially on colored paper), is more difficult to read than good-quality black printing on a white background. Determining which colors on which background enhance visibility can be highly individual. Generally, white on black or black on white provides the best contrast, but may not be available for all tasks. Trial and error can determine an individual's best color combinations. White paper is more visible against a dark desk top or blotter. Black felt-tip pens provide more contrast than standard ballpoint pens or pencils. Putting contrasting· tape or paint around light switches, outlets, and other small controls makes them easier to locate. Appropriate color-contrast modification may substantially increase an individual's visual functioning. 18 Color contrast should be provided or enhanced for distance and mobility as well as near work tasks. Furniture and equipment should
Visually Impaired Older Workers
contrast with background walls and floors. When possible, light walls with dark furniture are preferred because lighter walls reflect more light, making the room more visible. Doors and doorframes are easier to locate when painted in contrasting colors to surrounding walls. Contrasting tape or paint on the edge of each step, or on the first and last step, aid depth perception and increase safety on stairs. Extreme lack of contrast can affect one's orientation as visual references may be few or absent. For this reason, travel areas should provide contrasting cues such as a dark border at the bottom edge of the wall if the wall and floor are the same color. However, care should be taken when adapting the environment using color contrast: enhancement of too many environmental features creates figure-ground confusion 19 resulting from visual clutter. Locating an object on a cluttered desktop or patterned surface can be difficult. Busy patterns and prints for large areas such as walls, rugs, floor patterns, and tablecloths should be avoided because smaller objects are difficult to locate against them. Solid colors limit the effects of visual clutter and figureground confusion. Organization of work space is critical to safe and efficient visual functioning. Items frequently used should be kept in easily accessible locations; unnecessary items should be removed from the immediate work area. When items have a particular location in a room, closet, or drawer, they are more readily and appropriately used and the need for visual searching is minimized. Files and storage areas may be color coded, taking care to avoid like colors in the violet-blue range ofthe spectrum. Travel areas and floors should be kept free of clutter and low-hanging objects which an individual with limited peripheral vision may not see. Wall-mounted ashtrays and water fountains may be unseen obstacles if they do not adequately contrast with their background walls. Keep doors all the way opened or all the way closed. Always close drawers and cabinets after use. When the work environment is shared with others, coworkers must be edu-
27
cated in the importance of the techniques of organization.
Vision Substitution/Blind Techniques In some instances, vision substitution or blind techniques may be needed for the visually impaired individual to function safely and effectively in certain tasks or areas. These techniques include enhancement of other senses, especially touch. When an individual travels in an unfamiliar area or one with poor lighting and color contrast, trailing or lightly touching the wall while walking aids orientation and safer travel. Holding stair railings is also helpful. Tasks such as typing and dialing a telephone are often done by touch even by individuals without vision loss. Localizing and discriminating sounds can aid in identifying one's location. Tape recording meetings and lectures eliminates the need for note taking. Braille and speech synthesizer computer adaptations are other nonvisual techniques. In some cases, a reader, someone who reads necessary information to a visually impaired individual, may be the only adaptation needed for the individual to remain in his or her current job.
Training and Education Adequate training in the use of adaptations, techniques, and devices, as well as education about the cause of vision loss, the resultant visual limitations, and the extent to which an individual may functionally use his or her vision is vital to the rehabilitation process. The individual must be instructed in the general concepts of enhanced lighting and color contrast to best adapt them for individual use. Optical devices and visual skills require adequate training; without it, these devices and skills will not be used to best advantage. Education of the employer and coworkers will increase their understanding of the problem and encourage them to assist in maintaining an organized environment.
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CONCLUSION Normal age-related visual changes need not force an individual into early retirement or a change of jobs. The visually-impaired person may compensate for these visual changes with an appropriate reading or bifocal prescription increased lighting and color contrast, minimal glare, larger print, less visual clutter, and organization of the work environment. All of these can usually be accomplished with relative ease and at minimal cost. For those with more severe visual impairment associated with disease, job retention is also possible, though the intervention and rehabilitation process is likely to be more extensive.
Job modification should involve the services of a vision rehabilitation service, as well as intervention (if appropriate) from the state agency serving the legally blind population. Optical and technological devices and visual skills training will likely be part of the job modification, in addition to those techniques used by individuals with normal age-related visual changes. For both groups, education and training are crucial to successful rehabilitation and the ultimate goal of job retention. The greater the awareness of the visually impaired individual and the employer of the problem and resultant visual limitations, the greater the opportunity for safe and efficient functioning on the job.
REFERENCES 1. Dickman IR: Creating Careers for Blind People: Rehabilitation and Technology. New York: Public Affairs Pamphlet no. 645, 1986.
2. American Academy of Ophthalmology: Eye Carefor the American People. San Francisco, CA: American Academy of Ophthalmology, 1988. 3. Morse AR, Silberman R, Trief E: Aging and visual impairment.] Vis Impair Blind 1987; 81: 308-311. 4. MorseAR, O'Connell W,JosephJ, Finkelstein H: Assessing vision in nursing home residents. ] Vis Rehabil1988; 2:5-14.
5. Kirchner C, Peterson R: The latest data on visual disability from NCHS. In Kirchner C, Data on Blindness and Visual Impairment in the US. New York: American Foundation for the Blind, 1985, pp 21-26. 6. Kirchner C, Peterson R: Employment: Selected characteristics. In Kirchner C, Data on Blindness and Visual Impairment in the US. New York: American Foundation for the Blind, 1985, pp 161-169.
7. American Foundation for the Blind: Visually Impaired Professional Personnel. New York: American Foundation for the Blind, 1981. 8. Cullinan T: Visual disability and blindness. In Visual Disability in the Elderly. London: Croom Helm, 1986, pp 1-13.
9. DeSylviaDA: Low vision and aging. Optom Vis Sci 1990; 67:319-322.
10. Sekuler R: Aging visual function. NCVA Aging and Vision News. New York: 1990. 11. Cristarella MC: Visual functions of the elderly. Am] Occup Ther 1977; 31:432-440. 12. Weale RA: Age and light. In The Aging Eye. New York: Harper and Row, 1963, pp 168174. 13. Weale RA: Spectral sensitivity and color vision. In TheAgingEye. New York: Harper and Row, 1963, pp 154-167. 14. Committee on Vision, National Research Council: Work, Aging, and Vision: Reportofa Conference. Washington, DC: National Academy Press, 1987. 15. Cullinan T: Eye diseases that limit sight in later life. In Visual Disability in the Elderly. London: Croom Helm, 1986, pp 33-54. 16. Jose RT: Optics. In Understanding Low Vision. New York: American Foundation for the Blind, 1983, pp 187-210. 17. Cullinan T: Lighting, contrast and colour. In Visual Disability in the Elderly. London: Croom Helm, 1986, pp 73-79. 18. Sicurella VJ: Color contrast as an aid for visually impaired persons. Vis Impair Blind 1977; 171 :252-258. 19. Cooper BA: A model for implementing color contrast in the environment of the elderly. Am ] Occup Ther 1985; 39;253-258.
Visually Impaired Older Worker
Jan K. Connolly, O.T.R.ll. Vision Rehabilitation Specialist/Consultant Arlington, Massachusetts
Every year, skilled, experienced people in the work force lose their sight. Although vision impairment can date from birth or be due to subsequent illness or accident, in two-thirds of all instances it is related to aging. 1 The American Academy of Opthalmology reports that the prevalence of eye disease increases throughout life from 1 % of preschool children to 85 % of older adults. 2 Visual impairment represents the third most common limiting function among the aged3 and vision is among the first of the senses to weaken with age. 4 The incidence of visual impairment increases with age from 1 person per thousand under 45 years of age to 6 persons per thousand aged 4564, and to 44.5 persons per thousand aged 65 and 0lder.5 The population in the United States is aging. In about 40 years, almost one-third of the population will be age 65 or older. 4 This increase in the aging population, paired with the fact that age is the single most significant predictor of the prevalence of visual impairment, indicates that the population ofindividuals with visual impairment will continue to grow and that more visually impaired people will be in the work force. Less than one-third of working-age (18-64 years) visually impaired people are in the labor force (either working or actively seeking work), compared to almost three-fourths of the general population. 6 However, this does not distin-
guish between those who are congenitally or adventitiously visually impaired early in life and those who begin to lose their vision later in their working years. Underemployment is common for the blind and visually impaired population, though the reasons for this have not been identified. 7 People with vision loss are underrepresented in professional, managerial, and clerical positions and overrepresented in manual occupations. Although the research does not identify why this is so, the former set of occupations emphasize reading and tend to pay better. 6 In many cases, especially among those who begin to lose their vision later in their working careers, necessary accommodations which would permit them to continue to function in their current jobs are available and possible. Employers are more likely to accommodate a visually impaired person already employed and trained in his or her position when vision begins to faiU Often, only a small portion ofthe job, involving reading or detailed work, causes difficulty. The intent of this article is to focus on those individuals already in the work force who begin to experience vision loss later in their working years. What follows is a discussion of possible problems and solutions that may allow aging visually impaired workers to remain in their jobs. The focus for these individuals is on relearning and adapting tasks they have done all along rather than learning new and unfamiliar tasks. However, it should be understood that there is not always a solution for every individual and for every job task. In some cases it may be necessary to reassign isolated aspects of ajob WORK 1991; 2(1):19-28 Copyright © 1991 by Andover Medical Publishers, Inc.
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or to change pOSItlOns completely, but often this need not occur when problems are addressed individually with creativity and technology.
DEFINING THE POPULATION Several terms are used to describe the visually impaired population, including blind, legally blind, and visually impaired. Blindness is frequently used to describe the sight of any individual with limited vision, including those who are totally blind (no light perception). Fewer than 1 in 20 "blind" people have no light perception; almost all have usable residual vision. 8 Legal blindness is an arbitrary cut-off point in the continuum of visual impairment developed to determine eligibility for registration with state agencies serving the blind and visually impaired. These agencies exist in every state and provide many benefits and services to registered individuals. Legal blindness means that vision in the person's better seeing eye is worse than 20/200 with correction or the field of vision in the better seeing eye is no more than Table 1.
20° (normal is 180°). Eighty percent of those who are legally blind have usable vision, 1,3 and more than two-thirds are over age 55. 3 Impaired vision can refer to any degree of vision loss from minimal loss up to and including total blindness. For the purpose of this article, visual impairment will describe individuals whose vision loss in some way limits their functioning. It should be understood that these terms do not take into account how well individuals use their vision. Many individuals who are legally blind are able to function quite well in their environments. In fact, two individuals with the same visual disease and measurable degree of vision loss will often function very differently. Solutions or adaptations for problems caused by vision loss are highly individual.
NORMAL AGING OF THE VISUAL SYSTEM Normal changes in the aging visual system can lead to functional difficulties. 9 As one ages, visual acuity - the ability to read (or see) small
Considerations for the Effects of Normal Aging on Vision
Visual Effects of Normal Aging
Treatment
Decreased visual acuity
Appropriate eyeglass prescription Large print materials
Decreased accommodation (presbyopia)
Appropriate reading or bifocal prescription
Narrowing of visual fields
Education of worker Increased lighting and contrast, especially in areas of mobility
Diminished visual search
Train in organized scanning techniques
Decreased color discrimination in violet/ blue range
Avoid like colors in violet/blue range Educate worker on deficit
Increased glare sensitivity
Cover/eliminate glare sources Tinted lenses
Increased need for light
Supplemental lighting for near tasks Adequate, even ambient lighting
Slowed light/dark adaptation Increased figure-ground confusion/ visual clutter
Good lighting, especially in entranceways Solid colors for backgrounds Avoid busy patterns and prints for large areas Organization of work area/materials
Slower visual processing speed
Maximize visibility of objects, tasks and environment through all of the above techniques
Decreased confidence in performing visual tasks
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details - declines. 10 Visual acuity is best at age 18 and gradually declines until age 40, after which an even sharper decline occurs. II Accommodation, the ability of the eyes to focus on objects at varying distances, decreases with age. The ciliary muscle of the eye loses some of its tone and power to control lens thickness, resulting in decreased accommodation. 3 Beginning at age 40, it is increasingly difficult to focus on near objects. This condition is called presbyopia and is usually correctable with glasses. The pupils get smaller as one ages, allowing less light into the eye and requiring increased illumination. lo A 60-year-old retina receives approximately one-third the amount oflight as a 20-year-old retina. 12 Increased sensitivity to glare and longer light/dark adaptation time are also seen. Glare is caused by an object reflecting excessive light back into the eyes due to too much or the wrong kind of light. II Light/dark adaptation is the ability of the eyes to adjust to changes in lighting levels. It takes longer for the aging eye to adjust to abrupt changes in lighting levels, as may be encountered when entering a dark storeroom from a brightly lit work area. Visual search begins to diminish in the 50s, and visual field gradually narrows with age. IO •11 It is harder to see violet and blue due to yellowing of the lens. 13 Increased sensitivity to glare, increased need for light, and decreased color discrimination may all contribute to decreased contrast sensitivity. An aging person is less able to deal with visual clutter and figure-ground confusion. An object viewed against a "busy" background is harder to see. In addition, slower speed in visual processing and decreased confidence in performing visual tasks have been reported. 14 See Cullinan8 and Weale 3 for additional information on the underlying physiological processes of these functional results. The cumulative effects of the visual problems associated with aging hinder an individual's ability to perform visual tasks that were once done with ease. Solutions for these normal visual changes may be as simple as providing an appropriate reading or bifocal prescription,
21
increasing the amount oflight, color contrast, print size, and spatial organization, and minimizing glare and visual clutter (Table 1). Education of older employees and their employers should be emphasized in developing effective compensatory techniques and minimizing disability related to aging eyes. Increasing awareness of the normal effects of aging on vision, including when and why difficulties may be present (such as why one may see better at certain times of the day or why some tasks provide better contrast, and thus are more visible than others) is the first step toward developing effective strategies for dealing with these limitations.
COMMON EYE DISEASES ASSOCIATED WITH AGING The four most common eye diseases associated with aging include cataracts, macular degeneration, glaucoma, and visual complications from diabetes.
Cataracts A cataract is an opacity or clouding of the lens of the eye behind the pupil. As lens becomes cloudy, passage of light to the retina, where images are formed, is blocked. Development of a cataract can lead to degradation of images, glare disability, reduced acuity and contrast sensitivity, and impaired color perception. 9
Macular Degeneration Macular degeneration is caused by the deterioration of the light-sensitive cells and the pigment cells in the small center part of the retina (the macula), which is responsible for fine detailed vision and color vision. Initially, this may affect only one eye and not impair function, but the condition is progressive and eventually will affect both eyes. The rate of progression is highly variable among individuals. Functional manifestations include central distortions, decreased acuity, central scotomas (blind spots), increased sensitivity to glare, and reduced contrast sensitivity and color discrimination. 9
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Glaucoma Glaucoma occurs when the pressure inside the eyeball rises above normal and affects the blood supply to the retina and optic nerve; it is almost always caused by failure of the fluid inside the eye to drain adequately.15 Functional losses that occur with glaucoma include reduced visual function in dim light, reduced contrast sensitivity, glare disability, peripheral field loss, increased light/dark adaptation time, reduced color discrimination, decreased acuity, and central field loss.9
Diabetic Retinopathy Diabetic retinopathy is caused by the deterioration of the blood vessels feeding the retina at the back of the eye. Abnormal blood vessels grow and bleed into the vitreous, the clear gel filling the center of the eye that gives the eye its shape. When leaking blood or fluid damages or scars the retina, the image sent to the brain is blurred. Functional losses resulting from diabetic retinopathy include reduced contrast and visual acuity, glare disability, scotomas, field loss, and reduced light/dark adaptation abilities and color discrimination. 9 Individuals with disease-related visual impairment may require more involved solutions and adaptations to continue functioning on the job than individuals experiencing only the normal effects of aging. Interventions should include an eye examination by an opthalmologist to diagnose and provide medical intervention for the eye disease and a comprehensive functional vision evaluation by a vision rehabilitation service or low vision clinic to determine the amount of remaining functional vision; prescription of optical devices and training in their use, as well as other nonoptical devices and techniques, may also be indicated. An individual determined to be legally blind should register with the state agency serving the blind and visually impaired to be eligible for services provided by the agency, including rehabilitation' vocational counseling, and orientation and mobility training. Additional interventions should include employee/employer education, environmental and work task evaluation and adaptation (including enhanced lighting
and color contrast, glare control, visual skills training, organization of work area), and devices (including magnifiers, computer adaptations, and other sensory and technological devices) (Table 2). Thorough training in the use of all necessary devices and adaptations is crucial to the success of the rehabilitation process.
EVALUATION A comprehensive evaluation is necessary to identify the visual requirements of the job. Once tasks involving vision are identified, task analysis further isolates the specific visual components within each task that cause functional problems. It may also be necessary to assess the degree of flexibility in the worker's job responsibilities in case certain job tasks must be reassigned. The work environment must also be analyzed, including the individual's work station or desk area, areas of travel such as entranceways, hallways, stairs, and storage areas, and other areas such as bathrooms, conference rooms, and cafeteria. These areas should be assessed for lighting levels and color contrast. After evaluation, the specific aspects of the job and environment that present difficulties should be identified. It may then become apparent that relatively few tasks or isolated components of tasks need adaptation, rather than the entire job. When looking for reasonable and functional solutions, remember that each individual is unique and several devices and/or techniques may be tried before arriving at a solution acceptable to both worker and employer. Involving the employer in the rehabilitation process may help. The more the employer understands the worker's needs, the more open he or she may be in providing or allowing the necessary devices and adaptations.
THE REHABILITATION PROCESS Optical and N onoptical Devices There are four ways to enlarge an image on the retina: relative-size magnification, relative
Visually Impaired Older Workers
Table 2.
23
Considerations for the Effects of Visual Disease Associated with Aging
Effects of Disease on Vision
Treatment
Degradation of images
Enhanced lighting and color contrast
Increased glare sensitivity
Cover/eliminate glare source Tinted lenses
Decreased visual acuity
Optical devices CCTV, computer adaptations Large-print materials Enhanced lighting/color contrast Move closer to object of view
Decreased color discrimination especially in violet/blue range
Enhanced color contrastllighting Avoid like colors in violet/blue range Individual assessment to determine best color combinations for contrast
Central distortions/scotomas
Train in eccentric viewing Optical magnification CCTV, computer adaptations Large-print materials Enhanced lighting/contrast Move closer to object of view
Increased need for light
Supplemental lighting for near tasks Adequate, even ambient lighting Illuminated optical devices Carry flashlight or penlight
Visual field loss
Mobility training Training in systematic scanning techniques Keep travel routes free of clutter/obstacles Tinted lenses Good lighting, especially in entranceways Wait for eyes to adjust to abrupt changes in lighting before moving
Slowed light/dark adaptation
distance (approach) magnification, angular magnification, and projection magnification. 16 Relative size magnification involves making the object itselfbigger. The most common example of this is large print materials. Relative distance magnification is achieved by bringing the object closer to the eye, such as holding printed material up close or moving closer to the object of View.
Angular magnification involves the use of optical systems, including hand-held, stand, and spectacle-mounted magnifiers, and telescopic devices. Some of these are designed for near and intermediate visual tasks while others are designed for distance-viewing tasks and mobility. These optical systems should always be prescribed by a vision rehabilitation service to ensure that the most appropriate and functional
device is obtained. An individual may be prescribed several different optical devices for specific tasks. For this reason it is important that the worker, when evaluated for these devices, be specific about the tasks he or she must accomplish at work, at home, and in travel. These devices are designed either for monocular or binocular use. Hand-held magnifiers can be illuminated or nonilluminated, may fit in a pocket, or may be attached to a spring arm for hand-free use. Generally, the larger the lens, the weaker its power, so an individual in need of a strong magnification may be limited by smaller lens size and thus a smaller field of view. Hand-held magnifiers are generally used for relatively short-term near and intermediate tasks such as reading dials, controls, and labels, or referring
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to papers during a meeting or conference. One must be trained which eye to use, how far to hold the lens from the eye and from the object, and how to coordinate movement ofthe magnifier to keep one's place on the page or object of View.
Stand magnifiers differ from hand-held magnifiers in that they are placed directly on the surface of the object of view and have a fixed focal distance. They are useful for longer term viewing of near and intermediate tasks since they need not be held at a precise working distance and are slid along the page or object of view. Stand magnifiers are also helpful for individuals with arthritis, tremors, or other physically limiting conditions that prevent them from holding and manipulating a hand-held magnifier. Stand magnifiers are available with or without illumination. As with hand-held magnifiers the stronger the power, the smaller the size of the lens. Techniques for use of stand magnifiers are similar to those for hand-held magnifiers. Microscopic lenses or spectacle-mounted magnifiers are essentially strong reading glasses. They are useful for longer term reading and leave both hands free to manipulate the reading material. However, the reading material must be held anywhere from 10 inches to less than 1 inch from the lens for the material to be in focus. Also, the field of view is limited: only one word, or even a portion of a word, may be visible at a time. The individual must learn which eye(s) to view with, how close to hold the reading material, and how to move the reading material across the line of vision to avoid constant refocusing and without losing his or her place on the page. Lighting is important when using spectacle-mounted, hand-held, or stand magnification. It is difficult to provide adequate direct light on the object being viewed, while maintaining the necessary working distance of the device, without causing glare. Telescopic devices are frequently prescribed for distance viewing, but are also made for intermediate distance and tabletop tasks. The telescope may be monocular or binocular, and can be hand-held or mounted in frames to
wear. Drawbacks of telescopes include limited field of view, the need to stand still and hold the telescope steady, difficulty in refocusing for objects at different distances, and locating the object to be viewed. Distance telescopes are used to view street and building signs, or people or visual demonstrations across a room. Telescopes designed for intermediate viewing may be used for assembly work (if done at a constant distance), writing, and other tabletop tasks. Projection magnification enlarges an image by projecting it onto a screen. The type of projection magnification most commonly used by the visually impaired is closed-circuit television (CCTV). This device uses a television screen with a camera mounted next to or under the screen, with a platform on which to place reading material underneath the camera. The image of the reading material is electronically enlarged on the screen. CCTV is expensive compared to other types of magnification, but is very useful. Unlike the other devices, CCTV can magnify images from 8-60 times. Until recently, CCTV was used mainly for reading and writing, but current developments include a lens that can focus on three-dimensional objects or detailed hand work required in some assembly work. The contrast and brightness of the image on the screen are adjustable, and one may choose either a positive (black print on a white background) or negative (white print on a black background) image. CCTVs are now available in color, which may be useful for working with color-coded circuit boards or color graphics. Aside from cost, the main drawback ofCCTV is that it is relatively stationary, although here, too, portable versions ofCCTV have been developed. Other projection magnifiers include slide and movie projectors. Most individuals will benefit from a combination of these four types of magnification. In addition to the many optical devices available, there is also a wide variety of nonoptical devices which can assist the visually impaired individual to function more effectively. Items such as writing guides - plastic templates that fit over a check or other frequently used form - allow one to write in the appropriate spaces and stay
Visually Impaired Older Workers
on the lines. Bold-lined paper is available, as are bold black felt-tip pens which may allow visually impaired individuals to read their own, as well as other's, writing. Large-print typewriters are also available, as are large-print telephone overlays for rotary and pushbutton phones, and large-print and memory phones. Special lighting is a non optical device which will be discussed in detail under the following section on environmental modifications. Bookstands are helpful for comfort and positioning, especially when used with a close-focusing magnifier, or when reading material must be held close to the viewer.
Sensory and Technological Devices Computer adaptations comprise the largest group of technological devices. The availability of computer adaptations has allowed many visually impaired individuals to remain in their jobs, and will continue to do so. Three basic types of computer adaptations are available: enlarged print, speech, and braille. Larger print can be obtained by using a larger monitor, a screen magnifier, a large-print software package that provides adjustable magnification or characters of graphics on the screen, and large-print printers. Speech-synthesizing components can read out instructions and text from the screen. Other devices allow the user to input braille and read back what is on the screen by braille output. Braille printers are also available. In addition to computer adaptations, there are now a number of other "talking" devices on the market. These include talking scales, cash registers, calculators, and digital tools for machinists and mechanical or industrial engineers.
Visual Skills Training For certain types of vision impairment, visual skills training such as scanning or eccentric viewing may help to maximize functional use of vision. Organized scanning involves moving the head or eyes back and forth to take in more of the environment. An individual with peripheral field restriction may need to scan by mov-
25
ing the head from side to side to see a whole room and avoid tripping over unseen furniture or equipment, to view an entire desktop area to locate an object, or to avoid knocking an unseen item off of the desk. An individual with macular degeneration and a central scotoma (blind spot) may need to learn eccentric viewing, the technique oflooking around the scotoma and utilizing the peripheral vision. Both of these techniques must be learned and usually require considerable training.
Environmental Modifications Illumination and Glare Control. Some degree oflight is necessary to see. Some tasks require more light than others, especialiy those involving fine detail such as reading or those with poor contrast or a high degree of visual clutter. 17 The normally aging eye requires three times more light than the eye of a young adult. 12 When visual disease is present, the need for light becomes even more crucial to functioning. Thus, the amount oflight needed by an aging person is dependent on three things: the presence of age-related visual changes, the presence of eye disease, and the task at hand. 17 In addition to the need for more light, an increased sensitivity to light may occur, resulting in glare. Glare decreases visibility of an object or area by decreasing its contrast against the background, making visual functioning more difficult. A common problem faced by the older visually impaired population is how to get enough light without causing glare. Three general areas should be considered when adapting lighting: work station or desk areas where close work is done, general room or ambient lighting, and areas of travel such as hallways and stairs. For close work, direct supplemental lighting is needed; in fact, the more detailed and fine the task, the greater the need for direct supplemental lighting. An adjustable gooseneck or flexible neck reading lamp is most often used for this purpose. To avoid glare and get the most light on the work, proper bulb wattage
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and positioning are critical. A single reading light with a 60-watt bulb is often sufficient for reading and detail work if the light is placed at the correct angle and close enough to the work material. A high-watt bulb is not usually necessary and may generate too much heat when placed close to the work surface. A reading light with a white or silver lining reflects more light. Individuals performing detailed tasks away from a desk or stationary work area may find flashlights or penlights helpful. There should be sufficient ambient lighting when using a supplemental lamp for reading or using a computer screen, to avoid problems due to slower light/dark adaptation. If the surrounding environment is not adequately lit, momentary "blindness" may occur while the eyes adapt to extreme changes in lighting levels. Weale l2 states that if local illumination is raised, luminance of the area immediately surrounding the highly-illuminated work area should be raised to about one-third of that of the work area to eliminate apparent pools of darkness. 12 General ambient lighting should be constant, even, and uniform to avoid shadows or glare caused by bright spots. It is difficult to generalize about which type oflight is best. Many individuals with impaired vision prefer standard incandescent bulbs for close work and report that fluorescent lights are more visually fatiguing, possibly due to the flicker effect that fluorescent lighting can cause, while others prefer fluorescent lighting for close work. Fluorescent lighting can provide even lighting for general room illumination, but should be shaded or recessed to limit glare. Many visually impaired individuals use sunlight, .which can be a very good source of illumination when properly used. However, while some may prefer sunlight, it is not always available and provisions should be made for additional lighting on cloudy days or for nighttime work. When using sunlight for near work, the individual should sit with their back or side to the window. To minimize glare, sunlight should come from behind or over the shoulders. Bulbs, lampshades, and windows should be kept clean. A recent flyer sent out by the Boston
Edison Company states that dust can reduce light by as much as 15%. Also, worn out or flickering fluorescent bulbs should be replaced. Glare can be minimized by proper placement and positioning of lights and by covering any large shiny surfaces: highly polished floors can be covered with rugs or given a dull wax finish; shiny table tops can be covered with cloths; desk tops can be covered with a large desk blotter; and windows should have shades and (if possible) polarized glass. When adapting light to suit the visually impaired individual consider the following statement as a guideline: "Good sight needs good light; and good light is not only bright light but light tailored to the task and to the individual. "17 Color Contrast and Visual Clutter. Enhancing color contrast involves making an object more visible against its background. Even the complete absence of glare and the most appropriate lighting may do little to help a visually impaired person see an object if there is insufficient color contrast between it and its background. 18 For reading, print contrast is important. Poor-quality print, such as that from a dot matrix printer, newsprint, poor xerox copies, blueprints, or anything written in pencil (especially on colored paper), is more difficult to read than good-quality black printing on a white background. Determining which colors on which background enhance visibility can be highly individual. Generally, white on black or black on white provides the best contrast, but may not be available for all tasks. Trial and error can determine an individual's best color combinations. White paper is more visible against a dark desk top or blotter. Black felt-tip pens provide more contrast than standard ballpoint pens or pencils. Putting contrasting· tape or paint around light switches, outlets, and other small controls makes them easier to locate. Appropriate color-contrast modification may substantially increase an individual's visual functioning. 18 Color contrast should be provided or enhanced for distance and mobility as well as near work tasks. Furniture and equipment should
Visually Impaired Older Workers
contrast with background walls and floors. When possible, light walls with dark furniture are preferred because lighter walls reflect more light, making the room more visible. Doors and doorframes are easier to locate when painted in contrasting colors to surrounding walls. Contrasting tape or paint on the edge of each step, or on the first and last step, aid depth perception and increase safety on stairs. Extreme lack of contrast can affect one's orientation as visual references may be few or absent. For this reason, travel areas should provide contrasting cues such as a dark border at the bottom edge of the wall if the wall and floor are the same color. However, care should be taken when adapting the environment using color contrast: enhancement of too many environmental features creates figure-ground confusion 19 resulting from visual clutter. Locating an object on a cluttered desktop or patterned surface can be difficult. Busy patterns and prints for large areas such as walls, rugs, floor patterns, and tablecloths should be avoided because smaller objects are difficult to locate against them. Solid colors limit the effects of visual clutter and figureground confusion. Organization of work space is critical to safe and efficient visual functioning. Items frequently used should be kept in easily accessible locations; unnecessary items should be removed from the immediate work area. When items have a particular location in a room, closet, or drawer, they are more readily and appropriately used and the need for visual searching is minimized. Files and storage areas may be color coded, taking care to avoid like colors in the violet-blue range ofthe spectrum. Travel areas and floors should be kept free of clutter and low-hanging objects which an individual with limited peripheral vision may not see. Wall-mounted ashtrays and water fountains may be unseen obstacles if they do not adequately contrast with their background walls. Keep doors all the way opened or all the way closed. Always close drawers and cabinets after use. When the work environment is shared with others, coworkers must be edu-
27
cated in the importance of the techniques of organization.
Vision Substitution/Blind Techniques In some instances, vision substitution or blind techniques may be needed for the visually impaired individual to function safely and effectively in certain tasks or areas. These techniques include enhancement of other senses, especially touch. When an individual travels in an unfamiliar area or one with poor lighting and color contrast, trailing or lightly touching the wall while walking aids orientation and safer travel. Holding stair railings is also helpful. Tasks such as typing and dialing a telephone are often done by touch even by individuals without vision loss. Localizing and discriminating sounds can aid in identifying one's location. Tape recording meetings and lectures eliminates the need for note taking. Braille and speech synthesizer computer adaptations are other nonvisual techniques. In some cases, a reader, someone who reads necessary information to a visually impaired individual, may be the only adaptation needed for the individual to remain in his or her current job.
Training and Education Adequate training in the use of adaptations, techniques, and devices, as well as education about the cause of vision loss, the resultant visual limitations, and the extent to which an individual may functionally use his or her vision is vital to the rehabilitation process. The individual must be instructed in the general concepts of enhanced lighting and color contrast to best adapt them for individual use. Optical devices and visual skills require adequate training; without it, these devices and skills will not be used to best advantage. Education of the employer and coworkers will increase their understanding of the problem and encourage them to assist in maintaining an organized environment.
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CONCLUSION Normal age-related visual changes need not force an individual into early retirement or a change of jobs. The visually-impaired person may compensate for these visual changes with an appropriate reading or bifocal prescription increased lighting and color contrast, minimal glare, larger print, less visual clutter, and organization of the work environment. All of these can usually be accomplished with relative ease and at minimal cost. For those with more severe visual impairment associated with disease, job retention is also possible, though the intervention and rehabilitation process is likely to be more extensive.
Job modification should involve the services of a vision rehabilitation service, as well as intervention (if appropriate) from the state agency serving the legally blind population. Optical and technological devices and visual skills training will likely be part of the job modification, in addition to those techniques used by individuals with normal age-related visual changes. For both groups, education and training are crucial to successful rehabilitation and the ultimate goal of job retention. The greater the awareness of the visually impaired individual and the employer of the problem and resultant visual limitations, the greater the opportunity for safe and efficient functioning on the job.
REFERENCES 1. Dickman IR: Creating Careers for Blind People: Rehabilitation and Technology. New York: Public Affairs Pamphlet no. 645, 1986.
2. American Academy of Ophthalmology: Eye Carefor the American People. San Francisco, CA: American Academy of Ophthalmology, 1988. 3. Morse AR, Silberman R, Trief E: Aging and visual impairment.] Vis Impair Blind 1987; 81: 308-311. 4. MorseAR, O'Connell W,JosephJ, Finkelstein H: Assessing vision in nursing home residents. ] Vis Rehabil1988; 2:5-14.
5. Kirchner C, Peterson R: The latest data on visual disability from NCHS. In Kirchner C, Data on Blindness and Visual Impairment in the US. New York: American Foundation for the Blind, 1985, pp 21-26. 6. Kirchner C, Peterson R: Employment: Selected characteristics. In Kirchner C, Data on Blindness and Visual Impairment in the US. New York: American Foundation for the Blind, 1985, pp 161-169.
7. American Foundation for the Blind: Visually Impaired Professional Personnel. New York: American Foundation for the Blind, 1981. 8. Cullinan T: Visual disability and blindness. In Visual Disability in the Elderly. London: Croom Helm, 1986, pp 1-13.
9. DeSylviaDA: Low vision and aging. Optom Vis Sci 1990; 67:319-322.
10. Sekuler R: Aging visual function. NCVA Aging and Vision News. New York: 1990. 11. Cristarella MC: Visual functions of the elderly. Am] Occup Ther 1977; 31:432-440. 12. Weale RA: Age and light. In The Aging Eye. New York: Harper and Row, 1963, pp 168174. 13. Weale RA: Spectral sensitivity and color vision. In TheAgingEye. New York: Harper and Row, 1963, pp 154-167. 14. Committee on Vision, National Research Council: Work, Aging, and Vision: Reportofa Conference. Washington, DC: National Academy Press, 1987. 15. Cullinan T: Eye diseases that limit sight in later life. In Visual Disability in the Elderly. London: Croom Helm, 1986, pp 33-54. 16. Jose RT: Optics. In Understanding Low Vision. New York: American Foundation for the Blind, 1983, pp 187-210. 17. Cullinan T: Lighting, contrast and colour. In Visual Disability in the Elderly. London: Croom Helm, 1986, pp 73-79. 18. Sicurella VJ: Color contrast as an aid for visually impaired persons. Vis Impair Blind 1977; 171 :252-258. 19. Cooper BA: A model for implementing color contrast in the environment of the elderly. Am ] Occup Ther 1985; 39;253-258.
