Study: First signs of Alzheimer's may appear in your eyes (CNN/CNN Newsource)
Researchers found that a person's eye health may be able to help diagnose the disease.
That's because Alzheimer's begins in the brain decades before most symptoms appear.
So, most patients don't know that they have it until it's already progressed.
The study, published in the journal Acta Neuropathologica, is based on a trial with 86 subjects.
Scientists examined both their retinal and brain tissue samples for 14 years.
They found a connection between disease in the retina and cognitive function.
This means that doctors could one day use noninvasive eye screenings to diagnose Alzheimer's early.
That would allow patients to make lifestyle changes, which could delay the onset of symptoms or make them less severe.