2024-04-18 00:21:10
Numerous diseases can also be seen in the eyes. Now doctors have discovered that they also send early warning signs of cognitive decline.
How well someone can see and how quickly they can react can be an early indicator of later dementia. This is the result of a British study. In Norfolk, 8,623 people were monitored over many years.
At the end of the observation period (after twelve years), 537 participants had developed dementia. The researchers were now able to trace which factors preceded the diagnosis.
At the start of the study, participants were asked to complete a visual sensitivity test. The task: They had to press a button as soon as they saw a triangle form in a field of moving dots.
Deficits in processing visual impressions
People who later developed dementia were much slower to recognize this triangle on the screen than people who did not develop the disease. Study leader Eef Hogervorst explains the results in the magazine “Science Alert”: “Visual problems can be an early indicator of cognitive decline, as the toxic amyloid plaques associated with Alzheimer’s disease can initially affect areas of the brain that are linked to vision. ” On the other hand, parts of the brain associated with memory would be damaged as the disease progresses. Therefore, vision tests can detect deficits before memory tests do.
Other aspects of visual processing are also impaired in Alzheimer’s disease, such as the ability to see outlines of objects (contrast sensitivity) and to distinguish between certain colors. They may also have a harder time ignoring distracting stimuli, which can result in problems controlling eye movements. This in turn could impair your ability to drive in the early stages.
Facial recognition is also difficult early on
People with dementia also apparently have deficits in facial recognition – even in the early stages. There is evidence that they process faces of unknown people more inefficiently. Her eyes didn’t move with purpose. As a result, it is often harder for them to recognize people later.
Hogervorst further reports that some studies suggest that more eye movements can improve memory. This could also explain why people who watch more television and read appear to have better memory and a lower risk of dementia.
The authors emphasize: Since access to eye tracking technologies is very expensive, eye movements can so far only be used in the laboratory as a diagnostic tool for early-stage Alzheimer’s.