If you have diabetes for a while and you have poorly controlled it, that is your blood sugar remained high for prolonged period of time (several years), it could have damaged the tiny blood vessels called capillaries of many organs including the eyes.
When due to high blood sugar (hyperglycemia) in diabetes, the capillaries of the retinas of eyes may get damaged. These damaged capillaries can leak fluid and blood causing retina to swell and form deposits. This is called non-proliferative or background retinopathy.
In a later stage, known as proliferative retinopathy, new blood vessels grow on the surface of the retina. These newly formed capillaries are not as good as original ones, but are distorted and “brittle”— meaning that they can relatively easily bleed. This type of retinopathy is certainly more serious and can cause blindness.
The risk of having retinopathy increases as the period of time for which you had high blood sugar increases.
According to the American Academy of Ophthalmology, people with diabetes are 25 times more likely to become blind than those who are not diabetic,
In later stages of diabetic retinopathy, new blood vessels will grow on the retina in a distorted manner which can result in the formation of scar tissues. The end result could be detachment of the retina from the back of the eye. Retinal detachment can lead to blindness. Secondly, the distorted blood vessels can grow onto the iris which can result in glaucoma (narrowing of field of vision)
Although all diabetic persons are at risk for developing diabetic retinopathy, all do not develop it.
Long term exposure to hyperglycemia (high blood sugar) is the main cause of Diabetic Retinopathy. Exposure to hyperglycemia for 5 to 10 years can cause it. Apart from this wild fluctuations in the blood sugar levels (from hypoglycemia:<60 mg/dL to any degree of hyperglycemia, say, for example, 200 to 400 mg/dL or more) is another risk factor for developing diabetic retinopathy.
Unfortunately, initially there may not be any symptoms. Unfortunately again, you will have symptoms only after some damage has already been done. These symptoms include difficulty in reading or doing close work, double vision. If you have any of these symptoms, you should immediately visit the doctor. Actually it is more prudent to get your eyes checked for the so called dilated eye exam at least once every year even before you get these symptoms in order to avoid damage. You see, prevention is always better than treatment!
External links:
http://www.allaboutvision.com/conditions/diabetic.htm
http://www.mayoclinic.com/health/diabetic-retinopathy/DS00447
Click here to go to Complications of Diabetes page
