People who do have diabetes have a higher risk for blindness than people without it.
Some of these vision problems include: 
Glaucoma
People with diabetes are 40% more likely to suffer from glaucoma than people without it. The longer someone has diabetes, the more common it is. Risk also increases with age.
Cataracts
Many people without diabetes get cataracts, but people with it are 60% more likely to develop them. People with diabetes also tend to get cataracts at a much younger age and have them progress faster. With cataracts the eyes clear lens cloud up and block light.
Retinopathy
Diabetic retinopathy is a term used for all disorders caused by diabetes. There are two major types of retinopathy: non-proliferative and proliferated.
Non-proliferative Retinopathy: Is the most common type of retinopathy. This occurs when capillaries in the back of the eye balloon up and form pouches. Non-proliferated retinopathy can move through three stages (mild, moderate and severe) as more blood vessels become blocked.
Proliferative: In this form, the blood vessels are so damaged they close off and new vessels start growing in the retina. These new vessels are very weak and can leak blood, blocking vision. The new blood vessels can also cause scar tissue to grow. After the scar tissue shrinks, it can distort the retina or pull it out of place.
