Study: Vision to linked mental decline in seniors

Problems seeing things close-up can speed up the rate of mental decline in the elderly, a study published in the Journal of the American Geriatrics Society indicates.

Researchers examined the link between vision and level of mental functioning in 2,140 Mexican-American adults over the age of 65. What they found was that seniors who had problems with near vision (but not with distance) showed the steepest decline in mental functioning over a 7-year period.

At the start of the study, the researchers tested the seniors' close-up and long-distance vision, their hearing, and their level of mental functioning, based on a standardized test. They also noted participants' age, gender, marital status, education, medical history, and other factors. All of the participants were retested after 2, 5, and 7 years.

While some decrease in vision is normal as people age - often requiring reading glasses - older adults are at an increased risk for more serious vision impairment caused by cataracts, macular degeneration, and other eye-related problems.

In the study, seniors who had problems with near vision decreased on the mental functioning scale by 0.6 points after 2 years and decreased 0.1 point more per year than participants who could see at close range. But seniors with difficulty seeing things that were far away had no significant difference in mental decline from those who had no problem with distance vision.

Other factors that were linked with greater mental decline were poorer initial score on the mental function scale, greater age, lower educational level, being unmarried, symptoms of depression, and the number of limitations seniors faced with regards to their daily activities.

The exact reason for the link between near vision and rate of mental decline is unclear, but the researchers speculate that not being able to see things close up affects the level of brain activity by decreasing both active and passive visual stimulation. Keeping your brain active through activities such as reading or doing crosswords, and even by passively processing visual information, increases nerve activity in the brain and has been shown in studies to have a preventative effect against dementia and Alzheimer's disease.

And while it is impossible to prevent age-related vision problems altogether, you can protect your eyes by wearing sunglasses and catch eye problems early through regular eye exams.