RetGen

Glaucoma, macular degeneration and the effects of diabetes destroy photoreceptors and other neurons in the retina, the inner lining of the back of the eyeball. Unlike other cells in our bodies, neurons don't naturally regenerate. Once they're damaged, they -- and the eyesight of people with those diseases -- are gone for good.

Early findings by Duke University ophthalmology researcher Dennis Rickman and others indicate that stem cells indeed restore damaged retinas.

"The cells migrate to the area of injury, and in many cases appear to integrate into the tissue and differentiate into those cells," Rickman said.