If you have eye problems and diabetes, don't buy a new pair of glasses as soon as you notice you have blurred vision. It could just be a temporary eye problem that develops rapidly with diabetes and is caused by high blood sugar levels.
High blood sugar in diabetes causes the lens of the eye to swell, which changes your ability to see. To correct this kind of eye problem, you need to get your blood sugar back into the target range (70-130 milligrams per deciliter or mg/dL before meals, and less than 180 mg/dL one to two hours after a meal). It may take as long as three months after your blood sugar is well controlled for your vision to fully get back to normal.
Blurred vision can also be a symptom of more serious eye problem with diabetes. The three major eye problems that people with diabetes may develop and should be aware of are cataracts, glaucoma, and retinopathy.