Maintaining good eyesight may help mitigate an age-related decline in cognition, according to a new study in JAMA Ophthalmology.

A study of more than 2,500 U.S. adults who were aged 65 to 84 years at the beginning of the research found the rate of worsening vision was associated with the rate of declining function. More importantly, vision had a stronger influence on cognition than the reverse.

Study participants were assessed at the beginning of the study and two, six and eight years later. Visual acuity was measured using Early Treatment of Diabetic Retinopathy Study charts, and cognitive status was assessed using the Mini-Mental State Examination.

The investigators found that both visual acuity and MMSE scores worsened as the study went on. The percent of participants with MMSE scores indicating cognitive impairment increased from 11% at baseline to 20.6% after eight years. Worse baseline visual acuity was associated with worse baseline MMSE score, and the rate of worsening visual acuity was associated with the rate of declining MMSE score.

“Poor vision reduces older adults’ ability to participate in activities that help to maintain their well-being and leads to decrease in brain stimulation that could become a risk factor for cognitive function decline. …The findings from our research indicate that vision has a greater influence on MMSE score than vice versa and suggests that vision is the dominating factor of the vision-cognition association,” wrote lead author D. Diane Zheng of the University of Miami Miller School of Medicine, and colleagues.