Diabetic retinopathy is a condition associated with diabetes. Elevated blood sugar levels cause damage to the blood vessels of the retina. At first, there may be no obvious symptoms which is why it is incredibly important to undergo regular checks with your optician / optometrist if you suffer from diabetes. As blood vessels of the light sensitive tissue become more damaged they will cause blurred vision. Other symptoms include fluctuating vision, impaired colour vision, dark or empty areas of vision, spots or dark strings floating in vision. As the disease progresses it will eventually lead to complete loss of vision.