Diabetic retinopathy
Diabetic retinopathy is caused by damage to blood vessels in the tissue at the back of the eye (retina). Poor blood sugar control is a risk factor.
The first symptoms are a blurred effect, dark areas in the vision, and difficulties in perceiving colours. This can even lead to blindness.
Mild cases can be treated with strict diabetes control, while advanced cases may require intravitreal injections, laser treatment or surgery.