Diabetic eye disease refers to a group of eye problems that affect those with diabetes. Those with diabetes may suffer from diabetic retinopathy, diabetic macular edema, glaucoma, and cataracts. Diabetic retinopathy is the most common cause of vision loss among those with diabetes, and it is also the leading cause of blindness. Diabetic eye disease can affect many parts of the eye, including the retina, macula lens and optic nerve. All forms of diabetic eye disease have the potential to cause severe vision loss and blindness, which is why getting an annual eye exam is so important.