How Diabetes Affects Your Eyes
Eye Conditions Caused by Diabetes
Diabetic retinopathy is the most common diabetic eye disease and the leading cause of new blindness among working-age adults in the U.S., according to the NEI. High blood sugar damages the small blood vessels in your retina over time. These damaged vessels can leak fluid, swell, or grow abnormal new branches that bleed into the eye.
According to the NEI, diabetic retinopathy affects about 1 in 3 adults with diabetes. The condition progresses through stages, from mild nonproliferative retinopathy (small areas of vessel swelling) to proliferative retinopathy (abnormal new vessel growth). You may not notice any vision changes in the early stages, which is why screening matters so much.
Diabetic macular edema (DME) occurs when fluid leaks from damaged retinal blood vessels into the macula, the part of the retina responsible for sharp central vision. This swelling distorts your vision and makes reading, driving, and recognizing faces difficult.
DME can develop at any stage of diabetic retinopathy. You may notice that straight lines look wavy, that colors appear washed out, or that your central vision has a blurry spot. Your eye doctor checks for macular edema during your dilated exam using imaging technology that measures retinal thickness.
According to the AAO, diabetes increases your risk of developing cataracts at an earlier age and experiencing faster cataract progression. High blood sugar can cause changes in the lens of your eye that make it cloudy sooner than it would in someone without diabetes.
Diabetes also raises your risk of open-angle glaucoma. Elevated blood sugar may affect the drainage system of the eye, increasing intraocular pressure over time. Both cataracts and glaucoma are treatable when caught early through regular eye exams.
How Your Eye Doctor Screens for Diabetic Eye Disease
A dilated eye exam is the standard screening method for diabetic eye disease. Your doctor places drops in your eyes to widen your pupils, then examines your retina, optic nerve, and blood vessels using a slit lamp and special lenses. This allows your doctor to see damage that is invisible without dilation.
During the exam, your doctor looks for microaneurysms (tiny bulges in blood vessel walls), hemorrhages (areas of bleeding), cotton wool spots (signs of poor blood flow), and abnormal new blood vessel growth. Optical coherence tomography (OCT) imaging may also be used to measure retinal thickness and detect macular edema.
According to the AAO, two FDA-approved artificial intelligence systems can now screen for diabetic retinopathy. These AI tools analyze retinal photographs and provide an immediate result in non-specialist settings such as primary care offices and diabetes clinics.
AI screening expands access to diabetic eye screening, for patients who have difficulty getting to an eye specialist. A positive result from the AI system leads to a referral for a comprehensive evaluation with an ophthalmologist. The technology does not replace your eye doctor but helps identify patients who need to be seen sooner.
The AAO Diabetic Retinopathy Preferred Practice Pattern (2024) recommends the following schedule:
- Type 1 diabetes: annual dilated eye exam starting 5 years after diagnosis
- Type 2 diabetes: dilated eye exam at the time of diagnosis and at least once a year afterward
Your eye doctor may recommend more frequent exams if you already have retinopathy or if your blood sugar control has been inconsistent. Even with excellent blood sugar management, annual screening is still required because retinopathy can develop in well-controlled patients.
Protecting Your Eyes When You Have Diabetes
Tight glycemic control and blood pressure management are the most effective strategies for preventing diabetic retinopathy, according to the NEI and the AAO. Keeping your hemoglobin A1c, blood pressure, and cholesterol within your target ranges reduces the risk of blood vessel damage in your retina.
Work with your primary care doctor or endocrinologist to set blood sugar goals and adjust your treatment plan as needed. Small improvements in blood sugar control can make a measurable difference in your eye health over time. Your eye doctor and diabetes care team should communicate about your overall management.
Anti-VEGF (anti-vascular endothelial growth factor) injections are the standard treatment for center-involved diabetic macular edema and proliferative diabetic retinopathy, according to the AAO (2024). Your ophthalmologist injects medication into the eye to reduce abnormal blood vessel growth and fluid leakage. Most patients need a series of injections over months to years.
Laser treatment (photocoagulation) can seal leaking blood vessels and reduce the growth of abnormal new vessels. In severe cases of proliferative retinopathy, vitrectomy surgery removes blood and scar tissue from inside the eye. Treatment can stabilize or improve your vision when started early, which is why screening matters.
Do not wait for symptoms before getting screened. Diabetic retinopathy causes no pain and no vision changes in its early stages. The AAO emphasizes that diabetic eye disease is asymptomatic early and that annual dilated exams are the only way to catch it before vision loss occurs.
Between scheduled exams, contact your eye doctor if you notice blurry vision, floaters, dark spots, or difficulty seeing at night. These changes can signal progression of diabetic eye disease that needs prompt evaluation and possible treatment adjustment.
Diabetes and Vision Questions
You cannot eliminate the risk entirely, but tight blood sugar and blood pressure control reduce your risk of developing retinopathy and slow its progression if it has already started. Annual eye exams catch changes early, when treatment is most effective.
Not necessarily. Many people with early diabetic retinopathy maintain good vision with proper blood sugar management and monitoring. Even advanced retinopathy can be treated with injections, laser therapy, or surgery. The key is early detection and consistent follow-up with your eye doctor.
It can affect one or both eyes, and the severity may differ between them. Your eye doctor examines each eye independently during your screening exam. Treatment decisions are made separately for each eye based on the stage of disease found.
Yes. Rapid changes in blood sugar can temporarily change the shape of your lens, causing blurry vision that comes and goes. This effect is separate from diabetic retinopathy and resolves once blood sugar levels stabilize. If blurry vision persists, see your eye doctor to check for other causes.
Most people with diabetes can safely undergo cataract surgery. Your ophthalmologist will evaluate your retinal health and diabetic retinopathy status beforehand to plan the safest approach. Good blood sugar control before and after surgery reduces the risk of complications and supports healing.
Yes. Bring a list of all your medications, including insulin, oral diabetes drugs, blood pressure medications, and cholesterol medications. Some drugs affect your eyes or interact with eye treatments. Your eye doctor uses this information to provide safe, informed care.
Stay on Top of Your Diabetic Eye Care
Annual dilated eye exams are the single most important step you can take to protect your vision if you have diabetes. Schedule your screening and keep every follow-up appointment your eye doctor recommends.