National Geographic : 2016 Sep
A cure in sight 39 stem cells and bionic implants—won’t fall over- night. Most gains will be hard-won and incre- mental. Many a miracle cure will prove fleeting. When assessing the sight-restoring potential of gene therapy, stem cells, and retinal implants, it’s fair to view them as a sort of three-legged stool. Right now it’s unsteady—but strong enough to support our weight if we move care- fully in our quest to end untreatable blindness. The challenge of ending treatable blindness, though, is another matter altogether. ROUGHLY ONE IN EVERY 200 people on Earth— 39 million of us—can’t see. Another 246 mil- lion have low vision to degrees that impose moderate or severe limits. Vision loss also af- fects hundreds of millions more people, often relatives, devoted to aiding those who can’t see. These burdens alone justify the search for new treatments. Yet the eye is also getting in- creased attention because it provides a safe, ac- cessible spot to test treatments that might also be used elsewhere in the body. To start with, researchers can look directly into the eye to see what’s wrong and whether a treatment is working. Likewise, the eye’s owner can see out of it (or not), providing a quick, vital measure of function. The eye also offers feed- back such as pupil dilation or electrical activi- ty in the optic nerve. In addition, a researcher In a Riverside, California, movie theater, Terry Byland (center) can see shapes on the screen thanks to the Argus II retinal implant. From 2004 to 2010, Byland—who lost his sight to retinitis pigmentosa—helped scientists develop the implant system, which includes an eyeglass-mounted camera and portable processor.