It’s all in the eyes.
They say that eyes are a window into your soul — but research shows they might also serve as an early window into cognitive decline.
A study published in Neurology suggests a simple vision test could detect Alzheimer’s a whopping 12 years before a diagnosis.
Researchers asked over 8,000 healthy adults — 537 of whom later developed dementia — to complete a visual sensitivity test in which they had to press a button the moment they detected a triangle emerging from a field of shifting dots.
Those who later developed dementia performed significantly worse at this “triangle test” than those who remained in good cognitive health.
While Alzheimer’s is known for memory loss, scientists now believe early signs may appear in how well we see — long before forgetfulness kicks in.
“Visual issues may be an early indicator of cognitive decline as the toxic amyloid plaques associated with Alzheimer’s disease may first affect areas of the brain associated with vision, with parts of the brain associated with memory becoming damaged as the disease progresses,” the study’s authors wrote in the Conversation.
“So vision tests may find deficits before memory tests do.”
Some other visual issues that may serve as early warning signs of dementia are having difficulty discerning between colors like blue and green and controlling eye movement.
“People with Alzheimer’s seem to have an issue ignoring distracting stimuli, which may show up as eye-movement-control issues,” they wrote.
There’s also evidence to suggest that people with dementia don’t “imprint” faces the way that healthy individuals do — by scanning from the eyes to the nose to the mouth.
“People with dementia can sometimes seem lost, because they do not purposefully move their eyes to scan the environment, including that of the face of the people they have just met,” the study’s authors wrote.
“So this early issue in not recognizing people you have just met could be related to ineffective eye movement for new faces, rather than being a pure memory disorder.”
Previous studies indicate that eye movement helps improve memory, which the researchers note might explain why people who read more and watch TV are less likely to develop dementia than those who don’t.
Then again — they pointed out this could be because people who read and watch TV are more well-educated and engage their brain more.
A recent study found that being bilingual can delay dementia — possibly thanks to similar cognitive activity.
