Diabetic retinopathy (die-uh-BET-ik ret-ih-NOP-uh-thee) is a diabetes complication that affects eyes. It's caused by damage to the blood vessels of the light-sensitive tissue at the back of the eye (retina). At first, diabetic retinopathy may cause no symptoms or only mild vision problems.Diabetic retinopathy is caused by damage to the blood vessels in the tissue at the back of the eye (retina). Poorly controlled blood sugar is a risk factor.Early symptoms include floaters, blurriness, dark areas of vision and difficulty perceiving colours. Blindness can occur.Mild cases may be treated with careful diabetes management. Advanced cases may require laser treatment or surgery.