ElderWeb

Have you ever wondered why your glasses sometimes seem inadequate even when you just had your prescription checked? Results of a recent study indicate that "real world" vision in seniors may be worse than traditional eye tests indicate, and that a significant proportion of the older population may be legally blind in poor lighting conditions.

John Brabyn PhD, Directory of The Smith-Kettlewell Eye Research Institute (SKI) Rehabilitation Engineering Research Center for Blindness and Low Vision, presented results from the SKI study of vision in seniors at the annual American Society on Aging / National Council on Aging Conference in San Francisco, California. Dr.Brabyn pointed out that traditional vision tests measure vision under ideal conditions -- using high contrast black text on a white background and in good lighting conditions. On the other hand, the "real world" consists of many situations where people see low contrast information in low light or glare. For instance, information on LCD screens used in electronics, ATMs, appliances, and elsewhere consists of black text on a gray or green background, which is much harder to see than black text on a white background. Street signs are often seen against the glare of the sky, electronics often have black buttons on a black control panel, and all these situations make information much harder to see than in the ideal conditions of a doctor's office.

Many other vision studies exclude users over the age of 75, making it difficult to assess the impact of vision changes on older people, so the SKI study deliberately included a high percentage of older adults, including many over age 85. The study then evaluated vision for a broad age-range in "real world" conditions. Results indicate that glare, dim light, and contrast decrease vision in older people significantly more than for younger people. Researchers found that many older people who tested for normal vision using traditional tests became nearly blind when low contrast, glare, and/or low light were introduced. The impact of these additional factors varied significantly by age, with little impact to those under age 75 but exponentially increasing impact on those age 75 or older.

Dr. Brabyn indicated that someone age 85 or older with "normal" vision could have vision reduced to 20/200 (legally blind) in certain "real world" situations. He said a large percentage of the older population is legally blind in poor light conditions, maybe 70% if you add in low contrast and glare. Even those with good acuity are impaired in low contrast and glare and need a drastic increase in magnification to compensate, up to 125 times more than their "official" acuity would indicate.

What does this mean to seniors and those who work with them? It may be even more important than was previously realized to increase contrast, improve lighting, and reduce glare to ensure that older adults can discern signs and other critical textual information. In cases where those factors cannot be controlled, older adults may benefit from tools used by the blind that can read or speak information they cannot see.