A new study sheds light on how vision loss is linked to mental decline in seniors. For the study, University of Miami researchers analyzed health data from more than 2,500 adults, aged 65 to 84, who were followed from about 1993 to 2001

The investigators found that the rate of vision loss was associated with the rate of declining mental (cognitive) function. But mental function did not have a strong effect on vision, according to the report. The new report was published June 28 in the journal JAMA Ophthalmology.

The study is the first to show that eyesight is the dominant factor in the link between vision loss and mental function, according to lead author D. Diane Zheng, a doctoral candidate in the university's department of public health sciences. However, the study couldn't prove that vision loss was the cause of the mental decline.

Vision loss and mental decline

Researchers interviewed the participants 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.

Vision loss and mental decline are common in aging Americans, and this study suggests that preventing or treating eye problems may help protect against mental decline.

"The takeaway is that we need to pay more attention to preventing and treating vision loss to possibly reduce the rate of cognitive decline," study co-author David Lee said in a university news release. Lee is a professor in the department of public health sciences.