A study involving more than 2,500 older adults (65+) found that the rate of worsening vision was associated with the rate of cognitive decline. More importantly, vision has a stronger influence on cognition than the reverse.
The study finding suggests maintaining good vision through the prevention and treatment of vision disorders in old persons may be a strategy to lessen age-related cognitive changes.
https://www.eurekalert.org/pub_releases/2018-06/jn-via062718.php