Welcome to this Special Issue on Low Vision. As we age, changes occur throughout the body including the eyes. How often do you ask your patients about their vision? Does your intake form or evaluation form address vision? I have been an occupational therapist over 20 years. Before I specialized in low vision, only one intake form at one place that I worked at had a single question about vision. Vision is often taken for granted or overlooked. Ninety percent of the information that we bring in through the central nervous system comes in through vision. No matter how bad individuals' vision gets, they will still try to rely on their vision. Vision loss may result from macular degeneration, glaucoma, cataracts, diabetic retinopathy, stroke, brain injury, multiple sclerosis, Parkinson's disease, Alzheimer's disease, or other medical conditions.
Visual impairment is classified by individuals' level of visual acuity. Individuals with 20/20 vision have normal vision. Near normal ranges from 20/30 to 20/60 visual acuity. We typically start seeing patients in low vision rehabilitation when they have moderate low vision, which ranges from 20/80 to 20/160. At this level eye doctors may prescribe magnifiers that low vision specialists will train patients to use. In addition, activities and the environment will be adapted to better meet individuals' needs. Severe low vision ranges from 20/200 to 20/400. Legal blindness in the United States is defined by 20/200 visual acuity or worse. At this level electronic magnification and screen readers start to be integrated into activities as vision becomes less effective to use. Profound low vision ranges from 20/500 to 20/1000 visual acuity. Individuals may have challenges in ambulation and typically are referred to orientation and mobility specialists who specialize in travel for individuals with visual impairment. Near blindness is defined as 20/1250 to 20/2500 and vision is unreliable, and total blindness is defined as no light perception or no vision.
Areas of vision that are affected by age-related vision loss include visual acuity (near and intermediate), visual fields (central vision and peripheral vision), and contrast sensitivity. Neurological vision loss not only affects those areas, but also may affect oculomotor control, visual attention, scanning, pattern recognition, visual memory, visuocognition, and visual adaptation.
Vision is complex, and there is a need for all health care providers to address vision in older adults. Health care providers can determine whether accommodations need to be made for patients and whether further evaluation of vision is needed. When I started learning about visual impairment, I started asking my patients some basic questions about their vision. Do you wear glasses? Do you have problems seeing? Have you been diagnosed with a visual impairment? These simple questions allowed me to determine whether I needed to do further testing. If you work with older adults, this should be part of a normal evaluation. If you are working with older adults with neurological conditions, vision should be evaluated.
This issue addresses evaluations and interventions used in low vision rehabilitation, goal setting, digital literacy, fall prevention, physical activity, social determinants of health, telehealth, the impact of COVID, monocular vision, and dual sensory loss.
All health care providers should be screening vision in their older adult patients. Ninety percent of the information brought in through our central nervous system comes in through vision. Increasing the size of print, increasing contrast, and adding additional light are simple techniques that can be used in everyday practice to enhance the quality of visual sensory input. I hope you enjoy this issue and it prompts you to think about how you will address vision in your daily practice to ensure older adults' needs are being met.
Sincerely,
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Julie Ann Nastasi, ScD, OTD, OTR/L,
SCLV, CLA, FAOTA