Short summary: Diabetes can increase the risk of several eye problems, including diabetic retinopathy, cataracts, and glaucoma. Glaucoma often has no early symptoms, so regular dilated eye exams are one of the most important ways to protect vision.
Key takeaways
- Glaucoma damages the optic nerve and can cause slow vision loss before symptoms are noticed.
- Diabetes is linked with a higher chance of glaucoma and other eye problems, including diabetic retinopathy and cataracts.
- Diabetic retinopathy and neovascular glaucoma are related but different eye problems, and both need eye specialist care.
What glaucoma is
Glaucoma is a group of eye diseases that damage the optic nerve, the nerve that carries visual information from the eye to the brain. The National Eye Institute notes that glaucoma often develops slowly. Many people do not notice symptoms until vision has already been affected.
The most common type is open-angle glaucoma. Other forms, such as angle-closure glaucoma and neovascular glaucoma, are less common but can be serious. Treatment can include prescription eye drops, laser therapy, or surgery, depending on the type and severity.
How diabetes is connected
Diabetes can damage small blood vessels throughout the body, including in the eye. The best-known diabetes eye complication is diabetic retinopathy, where high blood sugar damages blood vessels in the retina. Diabetes is also linked with a higher risk of cataracts and glaucoma.
The CDC lists glaucoma among the eye problems that occur more often in people with diabetes. Diabetes can also lead to neovascular glaucoma in some people with diabetic retinopathy, when abnormal new blood vessels grow on the iris and interfere with fluid drainage inside the eye.
What symptoms should not be ignored
Many people with glaucoma have no early warning signs. Over time, side vision may slowly narrow. Because this can happen gradually, it may not be obvious day to day.
Sudden eye pain, nausea, red eye, blurry vision, halos around lights, or a sudden change in vision needs urgent medical attention. Those symptoms can occur with angle-closure glaucoma or other eye emergencies.
Eye exams matter even when vision seems fine
A comprehensive dilated eye exam lets an eye professional check the retina, optic nerve, eye pressure, and visual field when needed. Diabetes eye screening is mainly used to look for retinopathy and other diabetes-related changes. Glaucoma evaluation may include eye pressure, optic nerve, and visual field testing based on risk, symptoms, or exam findings.
ADA retinopathy standards recommend an initial dilated and comprehensive eye exam for adults with type 2 diabetes at diagnosis. For adults with type 1 diabetes, the first exam is recommended within 5 years after diabetes begins. Parents of children with type 1 diabetes should ask their pediatric diabetes team when eye screening should begin.
For more background, read our guides to diabetes complications, diabetic retinopathy, and the annual diabetes eye exam.
Practical takeaway
If you have diabetes, do not wait for blurry vision before booking eye care. Ask your clinician or eye specialist how often you need a dilated eye exam, especially if you have high blood pressure, kidney disease, retinopathy, a family history of glaucoma, or any new vision symptoms.
Sources
- National Eye Institute: Glaucoma
- CDC: Vision Loss and Diabetes
- American Diabetes Association: Retinopathy, Neuropathy, and Foot Care Standards 2026
Editorial review note: reviewed for medical accuracy, source consistency, patient-safety framing, plain-language readability, and urgent-symptom wording before publication.