Apparatus and methods for mapping retinal function: More than two million people older than 40 in the U.S. suffer from glaucoma. The disease—­one of the leading causes of blindness— is the result of damage to ganglion cells in the retina. Early-stage glaucoma is treatable, and the earlier it is caught, the easier it is to reverse. But catching glaucoma is not easy, because it often starts at the edge of the retina, beyond our usual field of vision. The standard way of detecting it is decades old and involves placing a contact lens with a single electrode embedded within it on the eye. The subject is shown a series of light flashes, and the electrode picks up the electrical responses from the retina. “What’s missing in that signal is any spatial differences in the health of the retina,” says John Hetling, a researcher at the University of Illinois.

It is difficult for doctors to determine if one part of the retina is healthy and another part is not. Hetling and his team wanted to improve on the standard method. They are working on a lens that holds far more electrodes—between 33 and 57. These extra electrodes allow for diagnoses of a larger area of the retina in far less time. Their device, patent No. 8,118,752, could also help detect other retinal diseases caused by diabetes, hypertension, sickle-cell anemia and premature birth.