The effect of diabetes on the eyes often involves several types of retinopathy, or conditions that affect the retinas of the eyes, and maculopathy, conditions affecting the macula. Different types of diabetes can also influence which type of eye disease occurs, such as in the case of proliferative diabetic retinopathy which is relatively rare and most often strikes those who suffer from type I diabetes. Especially in uncontrolled cases of diabetes with wildly varying blood sugar levels, vision loss is common as a result of cataracts. Changing blood sugar levels can also affect the eye lens, resulting in blurred vision that may change in severity throughout the course of the day. Not all people affected by diabetes experience any detrimental changes to their vision or eye health.
There are 3 main forms of retinopathy considered to be effects of diabetes on the eyes including diabetic retinopathy, background diabetic retinopathy, and proliferative diabetic retinopathy. In cases of diabetic retinopathy, leaking and blockages occur in the tiny blood vessels of the eyes, and eventually cause irreversible vision loss of varying severity. Background diabetic retinopathy is the most common type of retinopathy, and it is characterized by less severe blockages and leakage than diabetic retinopathy. The vision of the patient is very rarely affected and most people are unaware of the condition. With proliferative diabetic retinopathy, the large blood vessels in the eyes are blocked and the body compensates by trying to produce new vessels, which are weak, grow in the wrong locations, and are unable to restore proper vision function.
Especially for patients with uncontrolled blood sugar levels, lens problems may signal the effects of diabetes on the eyes. It is not unusual for extreme changes in the blood sugar levels to create changes in vision that can fluctuate as rapidly as several times in a day. When this type of situation occurs for a long period of time, it commonly causes cataracts to develop on the eye lenses. Cataracts are easy to recognize, as they produce a cloudy film over the surface of the eye, seriously impairing vision.
Another possible effect of diabetes on the eyes is the presence of maculopathy, a condition of retinopathy that affects the macula of the eye instead of the blood vessels. This eye disease changes the vision from the center of the eye, and the person affected often has difficulty distinguishing fine details such as small print or even the details of a person's face in the distance. It does not effect peripheral vision, and is frequently treated with laser surgery to preserve as much of the patient's vision as possible.