The eye is often compared to a camera, but although its basic design is as simple as an old-fashioned box Brownie, its detailed structure is more complex than the most advanced electronics. This means that, unlike simpler organs, studies of retinal disease rely heavily on animal studies, and treating such illnesses is extremely difficult. One ray of hope in the field comes from researchers at John Hopkins, who have constructed a functioning segment of a human retina out of stem cells that is able to respond to light.
via Gizmag
Image: John Hopkins
