Treating vision problems in older people may help prevent dementia, study finds

Detecting and treating vision problems in older people could help prevent one in five cases of dementia, say American researchers, whose work was published Thursday, September 5 in the online scientific journal JAMA Network. These researchers analyzed the visual and cognitive functions of more than 2,700 people over the age of 65. Their results indicate that 19% of cases of dementia can be attributed to visual impairment problems, whether it is difficulty distinguishing contrasts of light or color, seeing up close or, to a lesser extent, seeing far away.

How can poorer vision influence the onset of dementia? The cause-and-effect link is not clearly established, but there are two hypotheses. Either, vision problems mean that these elderly people engage less than average in activities that are known to protect the brain from aging, such as reading, social or physical activities, or cultural outings. Or, there is a degeneration process, which first manifests itself through eye problems and can sometimes lead to dementia. In all cases, early detection of visual disorders contributes to better medical care to delay brain aging, indicate the authors of the study. Especially since 90% of visual deficiencies are correctable.

Having good or bad vision therefore plays a role in age-related cognitive disorders, but having poor hearing can also play a role. Among these factors that increase the risk of developing dementia, we also find hearing loss, when it is not treated, lack of physical activity, excess cholesterol, hypertension, excess weight, smoking or excess alcohol. In general, prevention can play a large role in the speed of the onset of age-related cognitive disorders. Neuroscience researchers have published a vast synthesis in the medical journal The Lancet this summer. They established that approximately 45% of dementia cases could be prevented or delayed by acting on 14 risk factors at different stages of life.