In the early stages of diabetic retinopathy, small blood vessels weaken and leak fluid or tiny amounts of blood, which distort the retina. At this stage, the person may have normal vision or may experience blurred or changing vision.
In a more advanced stage, blood vessels in the retina are blocked or closed completely, and areas of the retina die. Proliferative diabetic retinopathy affects about five per cent of people with diabetes and occurs when new, abnormal blood vessels grow to replace the old ones. These new vessels are fragile and often rupture and bleed into the eye, blocking vision. Scar tissue forms, shrinks, and tears the retina, causing bleeding or detachment from the back of the eye. This can result in severe visual loss or blindness. Fortunately, this occurs only in a small minority of people with diabetes.
A sudden change in vision, blurred or distorted vision may be noticed making it difficult to read standard print and watching the television. There may be an increased sensitivity to glare and trouble with night vision. Eye floaters, spots, double vision and eye pain may also be present.