I'm not affiliated with Optina and I don't know specifically what they're doing, but the classic symptom of Alzheimer's is the formation in the brain of amyloid

I'm not affiliated with Optina and I don't know specifically what they're doing, but the classic symptom of Alzheimer's is the formation in the brain of amyloid plaques - and it appears to be the case that they also form on the retina, and can thus be detected by appropriate optical scans.