The retina is the light-sensitive tissue at the back of the eye. It detects light and sends signals that travel to the brain by way of the optic nerve to create the images that we see. Chronically elevated blood glucose levels associated with poorly controlled diabetes gradually damage the tiny blood vessels in the retina. The damage causes these vessels to leak fluid or bleed, distorting vision. In advanced cases, new, abnormal blood vessels grow (or “proliferate”) on the surface of the retina, which can cause scarring in the retina.

Having any kind of diabetes puts you at risk for diabetic retinopathy, and the longer you have diabetes, the greater your risk. Chronically elevated blood glucose, blood pressure, or blood cholesterol levels also increase the risk, as do pregnancy, tobacco use, or being Black, Hispanic, or Native American.