ABOUT THE RETINA: We can see because light reflects off objects in our surroundings and enters the eye through the pupil. The light is then focused and inverted by the cornea and the lens, and projected onto the back of the eye. There we find the retina, which is lined with a series of photoreceptors that convert the light signal into a neural signal. Ganglion cells then transmit those signals to the brain via the optic nerve.
TRANSPLANTING CORNEAS: Cornea transplants have traditionally only been performed in severe cases, since the majority of transplant recipients don't see improvements in their vision for at least six months, and even then strong glasses or contact lenses are needed because of remaining distortions. The cornea is slow to heal, and the transplant can remain vulnerable to injury for the rest of the patient's life. As many as 40,000 cornea transplants are performed each year in the United States. The most common reasons for performing the procedure are swelling, clouding after damage from other eye diseases, and scarring after injuries or infections. They are now being used with non-sighted patients and enjoying some success at providing improved vision.
The Materials Research Society contributed to the information contained in the TV portion of this report.