Narrator: This is Science Today. Cataract surgery is one of the most common procedures done in the elderly in the United States . During the surgery, cloudy lenses are removed and then an implant, usually made of plastic, silicone or acrylic, is placed inside the eye. Dr. Dan Schwartz, director of the retinal service at the University of California , San Francisco , says everyone requires a different powered lens.
Schwartz: It's just like shoe size and so before surgery, they measure the length of your eye and the curvature of your cornea and based on those measurements, are able to determine the power of lenses you need in your eye. But because of imprecision in the way the eye heals after surgery because of pre-existing things like astigmatism, a lot of times it's very difficult to predict exactly the power you're going to need until the eye is healed. And by that time it's too late because they lens is already in your eye. So probably 40 to 50 percent of patients, to get their best possible vision after surgery wear glasses.
Narrator: Schwartz and colleagues have developed light-adjustable lenses that can be reshaped with light after the eye has healed.
Schwartz: It's a way of, after surgery, modifying the power of the lens, which heretofore, had been impossible.
Narrator: For Science Today, I'm Larissa Branin.