Diabetic retinopathy is a frequent complication of diabetes.
An elevation in blood sugar damages the delicate blood vessels inside the eye, causing them to leak, bleed and become blocked. The damage from diabetic retinopathy is usually permanent. Diabetes can contribute to changes in nearsightedness, farsightedness and premature presbyopia (the inability to focus on close objects with age). The disease may also contribute to the onset of cataracts, glaucoma, strabismus (lack of eye alignment) and decreased corneal sensitivity.