Nearly 65 percent of adults aged 50 and over have vision problems. Although we know that poor vision can lessen an older adult's ability to function, until now not much has been known about how poor vision impacts an older adult's physical and cognitive (or mental health) abilities.

In a study published in the Journal of the American Geriatrics Society, researchers from German universities and medical schools studied 2,394 adults between the ages of 77 and 101 to learn how vision issues affected their physical and cognitive abilities.

Researchers interviewed the every 18 months between 2003 and 2012. They asked the participants how often they were physically active and what activities they performed, including cycling, long walks, swimming, gymnastics, garden work, or taking care of people. The researchers also asked how often the participants read, wrote, played music, worked on crossword puzzles, did memory training, played card games, board games, or chess, and how frequently they engaged in social activities.

Participants were asked to rate their visual impairment on a scale that included "no impairment," "mild impairment," or "severe or profound impairment." Researchers also asked whether participants had chronic conditions such as diabetes or stroke, and how severe the conditions were.

During a second group of interviews 36 months after the study began, most of the participants were women whose average age was 82. They were mostly single, widowed, or divorced, and lived alone. Nearly 80% of the participants reported having no .

But after the second wave, visual impairments increased over time, and the frequency of the participants' physical and mental activities decreased—especially for activities such as cycling, long walks, gymnastics, and gardening. Solving and reading also decreased as worsened.

The researchers concluded that when older adult's vision declines sharply, their participation in physical and mental activities also declines. The team suggested that, since most vision loss is preventable, strategies to postpone might also help delay physical and mental decline among older adults.

More information: André Hajek et al, Effect of Visual Impairment on Physical and Cognitive Function in Old Age: Findings of a Population-Based Prospective Cohort Study in Germany, Journal of the American Geriatrics Society (2016). DOI: 10.1111/jgs.14458

Journal information: Journal of the American Geriatrics Society