Written by Dr. Matthew Capozzi, DPM, FACFAS, CWS (board-certified foot surgeon and wound specialist) · Medically reviewed by the CircuFiber Scientific Advisory Board · Updated: October 27, 2026

Diabetic retinopathy is an eye complication of diabetes in which high blood sugar damages the tiny blood vessels in the retina, the light-sensitive layer at the back of the eye. It often has no symptoms in its early stages and may go undetected until it has already caused considerable harm to one’s vision. The risk of severe vision loss can be greatly reduced if the condition is detected early with a dilated eye exam and managed with good blood sugar control and, where needed, laser treatment, eye injections or surgery.

Key Takeaways

• Diabetic retinopathy is caused by high blood sugar levels damaging the tiny blood vessels in the retina. It is one of the most common complications of diabetes and a leading cause of vision loss in adults.
• It progresses through stages: non-proliferative diabetic retinopathy (NPDR), where weakened vessels bulge and leak, and proliferative diabetic retinopathy (PDR), where abnormal new vessels grow and can bleed into the eye.
• Early stages usually have no symptoms. Blurred vision, floaters, dark patches and trouble seeing at night tend to appear only after damage has been done, which is why annual dilated eye exams matter.
• Treatments such as laser therapy, anti-VEGF injections and vitrectomy surgery can slow or stop progression and sometimes recover part of the lost vision, but they cannot fully reverse established damage.
• The biggest levers you control are keeping blood sugar and blood pressure in range, not smoking, and getting a comprehensive eye exam at least once a year.

What is diabetic retinopathy?

Diabetic retinopathy is damage to the small blood vessels of the retina caused by prolonged high blood sugar. The tiny blood vessels inside the light-sensitive layer at the back of your eye are akin to roads in a city, with both playing vital roles. High levels of sugar within our system can lead to diabetic retinopathy, an issue that starts off silently and slowly damages these roads until they have leaks which cause blurry vision. If left untreated, it will enter a more advanced stage known as proliferative diabetic retinopathy, where abnormal new blood vessels grow into the vitreous (the jelly-like substance that fills the eye). This can be very damaging for one’s sight if not managed correctly and can eventually risk severe vision loss.

Diabetic retinopathy is one of several complications of long-term high blood sugar. Nerve damage in the feet, known as diabetic neuropathy, develops by a similar process of small-vessel and nerve injury, and the two conditions often occur together.

What are the stages of diabetic retinopathy?

Diabetic retinopathy progresses through four stages, from mild non-proliferative retinopathy to proliferative retinopathy. The progression is characterized by alterations in the small blood vessels of the retina, moving from a mild non-proliferative stage to moderate and then severe stages before arriving at the proliferative stage. The table below summarizes what happens in each stage and what it typically means for your vision.

Non-proliferative diabetic retinopathy (NPDR)

Non-proliferative diabetic retinopathy (NPDR) is the first stage, akin to small signs of degradation in our city’s roads. The walls of the blood vessels inside the retina become thin and weak, causing bulges that can start leaking fluid or blood into the eye, leading to blurry vision and other visual impairments. As this condition does not present many symptoms at its onset, these tiny outgrowths are usually only detected by looking closely at the eyes during an exam. If the leakage persists it can result in diabetic macular edema, which causes more blurring due to a decrease in central vision sharpness.

Proliferative diabetic retinopathy (PDR)

Proliferative diabetic retinopathy (PDR) is the advanced stage, a serious condition which, if left untreated, can cause permanent vision loss. As PDR advances, blood vessels that are damaged close off and lead to the development of abnormal ones. These new vessels are weaker than usual and prone to leaking into the vitreous, leading to severe visual impairment or complete blindness. At this stage, it is vital that treatments such as laser therapy, medication injections or surgery be sought out promptly, not only to stop progression but potentially to restore some sight too.

What are the symptoms of diabetic retinopathy?

The most common symptoms of diabetic retinopathy are blurred or hazy vision, dark spots or patches in your field of view, floaters, difficulty seeing at night and, in advanced disease, sudden loss of eyesight. In its initial phases there might not appear to be any visual signals at all, which is why recognizing the warning signs can be a daunting task. If you experience unexpected alterations in your eyes or find that your vision has gone blurry suddenly, urgent consultation with an eye care professional is highly recommended. Early diagnosis is vital for delaying deterioration and avoiding severe, permanent damage to one’s sight.

Early-stage symptoms

At the outset of diabetic retinopathy, symptoms can be faint and barely perceptible. You may not notice any changes at all, or just mild modifications to your vision such as blurred sight in certain lighting conditions or difficulty seeing clearly at night. These signs should act like a bell ringing far away, signaling that something is off-kilter. Regular eye examinations allow this disease to be identified quickly, with treatment prescribed immediately if needed.

Advanced-stage symptoms

Advanced diabetic retinopathy causes more obvious changes: decreased sight over time, sudden poor visibility or blurring of the field of view, floaters, blind spots, difficulty telling colors apart, and redness or pain in one eye. If you notice your vision changing in any way, don’t ignore it. A delay could lead to serious complications like severe and even total blindness. These symptoms may seem minor at first, but they can be warnings that require immediate attention from an eye doctor; if not treated quickly enough they can lead to profound and permanent loss of vision.

What causes diabetic retinopathy and who is at risk?

Diabetic retinopathy is caused by prolonged high blood sugar damaging the walls of the retina’s small blood vessels, and the risk rises with how long you have had diabetes and how well it is controlled. The risk of developing diabetic retinopathy can be increased by a number of factors, including age, duration of diabetes, poor control over blood sugar levels and high blood pressure. Lifestyle choices such as smoking and obesity should also be taken into consideration when assessing the potential danger for this condition. Recognizing the different causes that could increase your risk is vital if you want to reduce the threat of diabetes-induced vision loss; the controllable risk factors for diabetes overlap heavily with those for retinopathy.

Blood sugar control

Keeping your blood sugar levels stable is the single most important factor, akin to monitoring the city’s traffic. If done properly, it can help prevent damage to your retinal vessels and preserve vision health. To do this effectively, you must take medicine as prescribed by a doctor, eat nutritiously balanced meals and participate regularly in physical activities that help keep glucose values controlled. Managing diabetes proficiently significantly reduces the chances of developing diabetic retinopathy or experiencing sight loss.

Smoking, high blood pressure and pregnancy

Smoking, high blood pressure and pregnancy each raise the risk of diabetic retinopathy. Smoking affects the health of your blood vessels, which makes them more vulnerable to the damaging effects of high blood sugar. High blood pressure puts even more strain on these same vessels. Those who have diabetes and are pregnant need to manage their glucose carefully, since pregnancy can increase the chances of retinopathy developing or worsening. Frequent eye exams both during and after pregnancy help identify early signs before damage occurs; see our guide to gestational diabetes symptoms.

How is diabetic retinopathy diagnosed?

Diabetic retinopathy is diagnosed with a comprehensive dilated eye exam performed by an optometrist or ophthalmologist, sometimes supported by retinal imaging. Early detection is essential in order to prevent severe vision loss, which is why the dilated exam during a regular check-up holds such importance. Dilating the pupil with special drops allows your eye doctor to observe the retina clearly and recognize any signs of the disease, resulting in prompt intervention before it affects your sight.

Dilated eye exam

A dilated eye exam is the standard test for detecting signs of damage to the retina. Eye drops are used to widen the pupils, which gives your doctor an unobstructed view of the back of the eye. Early detection of diabetic retinopathy through this technique can help prevent vision loss and can identify leaking blood vessels or new vessel growth before they become more serious. A comprehensive examination that includes dilation gives invaluable insight into how healthy your sight currently is.

Imaging techniques: fluorescein angiography and OCT

Two imaging techniques are commonly used alongside the dilated exam to diagnose and monitor diabetic retinopathy. Fluorescein angiography involves injecting a specialized dye into the bloodstream and then photographing the retina to show any abnormalities or leaks from new vessels. Optical coherence tomography (OCT) uses light waves to scan the retina so that edema (swelling) or fluid leakage can be seen more easily, without the need for dye. Both methods give detailed views of how healthy the retinal blood vessel network is and help greatly with diagnosis and treatment planning.

How is diabetic retinopathy treated?

Diabetic retinopathy is treated with laser therapy, injections of medication into the eye, or surgery, depending on the stage. The best choice for you depends on the severity of your condition, any symptoms that are present and your overall health. Your healthcare provider will advise you on which method would work best for you personally; each option brings its own benefits when it comes to managing this eye condition. Alongside these procedures, good blood sugar control remains part of every treatment plan.

Laser therapy

Laser therapy (photocoagulation) can help address damaged blood vessels and scar tissue in the eye, particularly for those with diabetic retinopathy. It is achieved by concentrating lasers on the regions of concern to reduce vessel size and seal any leaks. There are possible side effects, such as loss of peripheral vision, night vision or color perception, so this option should be discussed carefully with your doctor before committing to it.

Medication injections (anti-VEGF and corticosteroids)

Injections of certain medications are often used to manage diabetic retinopathy. Medications such as anti-VEGF drugs and corticosteroids help inhibit the growth of abnormal blood vessels in the retina, acting like a traffic-calming measure for them. Despite its intimidating nature, this form of treatment can be successful and is generally well tolerated by patients. The proliferation and spread of harmful tissue from these vessels is slowed down, leading to an improved course when managing diabetes-related eye disease.

Vitrectomy surgery

For cases of advanced diabetic retinopathy, a surgical treatment called vitrectomy may be required. This procedure consists of removing part of the vitreous from the eye to address bleeding, scar tissue or other severe forms of diabetes-related vision problems. Following surgery, you will need to patch your eye for roughly one day and use eye drops to lessen inflammation and avoid infection. If a gas bubble was inserted during the procedure, you must maintain the head position your surgeon recommends so that it stays in place over several days or weeks after surgery.

How can you prevent diabetic retinopathy or keep it from getting worse?

You cannot guarantee that diabetic retinopathy will never develop, but keeping blood sugar and blood pressure in range, not smoking, and getting a yearly dilated eye exam can substantially lower the risk and slow progression. Much like traffic laws help avoid incidents on the road, regular eye check-ups and a lifestyle that keeps blood sugar levels stable will assist in preserving one’s vision.

Get a dilated eye exam every year

Regular eye exams allow your doctor to watch the status of your eyes and identify any initial signs of diabetic retinopathy before symptoms appear. The American Diabetes Association recommends that people with diabetes receive a thorough dilated eye examination at least yearly. If you are pregnant and have diabetes, more frequent eye exams become even more essential, since pregnancy can increase the risk of retinopathy developing.

Keep blood sugar in your target range

Maintaining your blood sugar within the range your care team prescribes protects your retinal vessels from harm and reduces the chance of diabetic retinopathy developing. Achieving this control requires following a balanced diet, engaging in physical activity regularly, adhering to medication instructions carefully and checking your blood sugar as directed. Regular exercise can help lower blood sugar and is one of the most practical tools you have.

Make healthy lifestyle choices

Healthy lifestyle habits lower retinopathy risk by improving blood sugar, blood pressure and weight. Regular physical activity helps bring down blood sugar levels and enhances overall well-being. A balanced diet is crucial for taking care of diabetes and stopping it from developing severe complications, and controlling weight gain matters too. A sound diabetic diet plan built on fruits, vegetables and whole grains helps regulate your blood glucose levels while sustaining a healthy weight. Avoiding smoking protects the same small vessels in your eyes, nerves and feet; taking good care of your diabetic feet is part of the same whole-body approach to preventing complications.

When should you see a doctor about diabetic retinopathy?

See an eye doctor the same day if you have diabetes and notice sudden blurred vision, a shower of new floaters, a dark curtain or shadow over part of your vision, or eye pain and redness, because these can signal bleeding into the eye or retinal detachment. Make a routine appointment if you notice gradual blurring, trouble seeing at night, difficulty reading or telling colors apart, or any change in your eyesight that lasts more than a day or two. Even with no symptoms at all, every person with diabetes should have a comprehensive dilated eye exam at least once a year, and more often if retinopathy has already been diagnosed or if you are pregnant. Vision loss from diabetic retinopathy is largely preventable with early detection and proper management, so do not wait for symptoms to appear.

Frequently asked questions about diabetic retinopathy

What are the 4 stages of diabetic retinopathy?

The four stages are mild non-proliferative, moderate non-proliferative, severe non-proliferative and proliferative diabetic retinopathy. The progression is characterized by alterations in the small blood vessels of the retina, moving from small bulges and leaks in the early stages to widespread vessel blockage and, finally, abnormal new vessel growth in the proliferative stage.

Can diabetic retinopathy be reversed?

Established damage from diabetic retinopathy is generally not reversible. There are treatments that can slow its advancement, prevent further damage and sometimes restore a portion of lost vision. Laser therapy seals off leaking blood vessels, anti-VEGF injections control the growth of abnormal vessels, and vitrectomy surgery may be required to remove blood or scar tissue from the eye. Catching the condition early, before the proliferative stage, gives the best chance of protecting your sight.

What are the signs of diabetic retinopathy in the eye?

People with diabetic retinopathy may experience blurred vision, dark spots or patches in their field of view, floaters and difficulty seeing during night hours. In the earliest stages there are often no signs at all, and the changes can only be seen by an eye doctor during a dilated exam.

What is the earliest symptom of diabetic retinopathy?

The earliest symptom is often mild blurring of vision, particularly in certain lighting or at night, sometimes with floaters or small patches in the visual field. Many people have no early symptoms, which is why the condition is usually first found during a routine dilated eye exam rather than because of a complaint.

What is the difference between non-proliferative and proliferative diabetic retinopathy?

Non-proliferative diabetic retinopathy (NPDR) is the early form, in which existing retinal vessels weaken, bulge and leak. Proliferative diabetic retinopathy (PDR) is the advanced form, in which the retina grows abnormal new blood vessels that are fragile and prone to bleeding into the eye. NPDR is usually monitored and managed with blood sugar control, while PDR generally needs active treatment such as laser therapy, injections or surgery.

How often should someone with diabetes have an eye exam?

The American Diabetes Association recommends a comprehensive dilated eye exam at least once a year for people with diabetes. Your eye doctor may ask to see you more often if retinopathy has already been found, if your blood sugar control has been poor, or if you are pregnant.

References, studies and sources

• National Eye Institute (NIH). Diabetic Retinopathy. https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/diabetic-retinopathy
• National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Diabetes: Health Information. https://www.niddk.nih.gov/health-information/diabetes
• American Diabetes Association. Diabetes information and standards of care. https://diabetes.org/
• Centers for Disease Control and Prevention (CDC). Diabetes. https://www.cdc.gov/diabetes/

About the author: Dr. Matthew Capozzi, DPM, FACFAS, CWS, is a board-certified foot surgeon through the American Board of Foot and Ankle Surgery. He is a Diplomate of the American Academy of Wound Management and Fellow of the American College of Foot and Ankle Surgeons. He completed a three-year residency program in Foot and Ankle Reconstructive Surgery at St. Francis Hospital & Medical Center in Hartford, CT in 2010. Dr. Capozzi is a board-certified Wound Specialist® granted by the American Academy of Wound Management.

Healthcare disclaimer: Always consult your physician before beginning any program. This general information is not intended to diagnose any medical condition or to replace your healthcare professional. If you experience any pain or difficulty, stop and consult your healthcare provider. CircuFiber socks are a general wellness product intended to promote a temporary increase in local blood flow and circulation; they are not intended to diagnose, treat, cure, or prevent any disease. Individual results vary.