If you have diabetes, your blood glucose, or blood sugar, levels are too high. Over time, this can damage your eyes. The most common problem is diabetic retinopathy. It is a leading cause of blindness in American adults.
Your retina is the light-sensitive tissue at the back of your eye. You need a healthy retina to see clearly. Diabetic retinopathy damages the tiny blood vessels inside your retina.
You may not notice it at first. Symptoms can include
Blurry or double vision
Rings, flashing lights, or blank spots
Dark or floating spots
Pain or pressure in one or both of your eyes
Trouble seeing things out of the corners of your eyes
Treatment often includes laser treatment or surgery, with follow-up care.
Two other eye problems can happen to people with diabetes. A cataract is a cloud over the lens of your eye. Surgery helps you see clearly again. Glaucoma happens when pressure builds up in the eye, damaging the main nerve. Eye drops or surgery can help.
If you have diabetes, you should have a complete eye exam every year. Finding and treating problems early may save your vision.
NIH: National Institute of Diabetes and Digestive and Kidney Diseases