Diabetes is a disease that affects blood vessels throughout the body, particularly vessels in the kidneys and eyes. When the blood vessels in the eyes are affected, this is called diabetic retinopathy.

The retina is in the back of the eye. It detects visual images and transmits them to the brain. Major blood vessels lie on the front portion of the retina. When these blood vessels are damaged due to diabetes, they may leak fluid or blood and grow scar tissue. This leakage affects the ability of the retina to detect and transmit images.

During the early stages of diabetic retinopathy, vision is typically not affected. As the retinopathy advances, new blood vessels grow in the retina. These new vessels are the body’s attempt to overcome and replace the vessels that have been damaged by diabetes. However, these new vessels are not normal. They may bleed and cause the vision to become hazy, occasionally resulting in a complete loss of vision. The growth of abnormal blood vessels on the iris of the eye can lead to glaucoma. Diabetic retinopathy can also cause your body to form cataracts.

The new vessels also may damage the retina by forming scar tissue and pulling the retina away from its proper location. This is called retinal detachment and can lead to blindness if left untreated.