Impaired near-range vision might enhance the rate of mental decline in older adults as they age. Researchers at the University of Texas Medical Branch in Galveston found that among more than 2,000 elderly Mexican Americans, those with significant impairments in their near vision tended to show a steeper decline in mental functioning over 7 years. The reason for the link is uncertain, but poor close-range vision may limit older adults' activities including mental exercises like reading and crossword puzzles thereby contributing to cognitive decline. In addition, lack of visual stimulation to the brain may affect the workings of nerve cells. The study, included 2140 Mexican-American adults aged 65 years and older who were periodically given standard tests of mental function over 7 years. At the outset, men and women were screened for impairments in their corrected vision; for the test of near vision, they were asked to read numbers from a card while wearing their glasses or contact lenses. Overall, 14 per cent of study participants had impaired near-range vision, while 7 per cent had problems with both near and distance vision. On average, the researchers found, these adults showed a quicker rate of decline on mental functioning tests over the next 7 years compared with their peers. There was no association, however, between mental decline and impairments in either distance vision or hearing. It is not clear, whether the treatment for low vision could have slowed the mental decline seen in some adults. The findings point to the importance of routine eye care for older adults, who are at an increased risk of vision-robbing eye diseases such as glaucoma, cataract and age-related macular degeneration. Depending on the disorder, treatment could involve a stronger lens prescription, vision aids such as a magnifying lens, medication or surgery. Researchers advised that older adults should try to take up mentally engaging activities such as reading, painting and solving crossword puzzles.
Journal of the American Geriatrics Society,
May 2005