The eyes are the window to the soul, and the brain

Scientists have found that they can peer into the brain - to diagnose Alzheimer's disease - by looking into the eyes. A paper in the journal PLoS One this week by Boston University researcher Lee Goldstein reveals how scientists have found that the beta-amyloid protein that causes Alzheimer's Disease when it builds up in the brain also accumulates in the lens, producing highly distinctive cataracts.

The researchers first made the link by studying patients with Down's Syndrome, who often go on to develop Alzheimer's Disease at a young age because they carry an extra copy of the gene that encodes the beta-amyloid, leading to over-production of the protein in the brain. But these patients also often develop cataracts, which are sometimes even present at birth, although prior to now no one realised that they were caused by the same substance that was triggering the damage to the brain.

Now researchers are looking to developing an eye test to spot these characteristic changes in the lens as an advance warning system for Alzheimer's.