Diabetic retinopathy includes several conditions that affect the light-sensitive layer of tissue on the back of the eye, known as the retina. This tissue is responsible for capturing light and passing on images to the brain.
When the retina doesn’t get enough blood, new blood vessels grow. These tend to be weak and can leak blood, which can cause vision loss or blindness.
Diabetic retinopathy can also cause vision loss when fluid leaks into the macula, the part of the retina that is responsible for the sharp, central vision. The leakage of fluid can lead to swelling of the macula (macula edema) and blurred central vision.