Diabetes Can Damage Your Eyes Before You Know It!

One of the biggest challenges with diabetes-related eye disease is that it does not necessarily announce itself through changes in vision. Damage to the retina can develop gradually, often without noticeable symptoms. This makes regular eye examinations an important part of long-term diabetes management, rather than something to consider only when vision deteriorates.

Observed on November 14, World Diabetes Day emphasises the need of comprehending and treating diabetes-related issues beyond blood sugar control. Eye health, in particular, often gets overlooked, as diabetes-related eye conditions can develop without noticeable symptoms, making regular eye examinations and timely screening essential.

How diabetes affects eye health

Prolonged high blood sugar can damage the tiny blood vessels supplying the retina, the light-sensitive tissue at the back of the eye. This condition, known as diabetic retinopathy, can weaken these vessels, causing them to leak fluid or blood. As the disease progresses, abnormal new blood vessels may develop, increasing the risk of bleeding, scar tissue formation and retinal detachment. If left untreated, diabetic retinopathy can lead to permanent vision impairment or blindness.

Another related complication is diabetic macular oedema (DME). The macula, located at the centre of the retina, is responsible for sharp, detailed vision. When damaged retinal blood vessels leak fluid into this region, it causes swelling that can affect central vision. Patients may experience difficulty reading, recognising faces or driving, activities that depend on clear and detailed vision.

Diabetes can also increase the risk of developing cataracts at a younger age and is associated with an increased risk of certain types of glaucoma, which can damage the optic nerve.

Risk increases with the duration of diabetes, poor blood sugar control and associated conditions such as hypertension and high cholesterol.

Why early detection is often difficult

Clear vision and well-controlled blood sugar are often mistaken for signs that the eyes are healthy. While good blood sugar control reduces the risk of complications, it does not eliminate the possibility of retinal damage.

Nor are retinal complications confined to people who have lived with diabetes for many years. They can also be present in individuals who have recently been diagnosed, particularly when diabetes may have remained undetected for some time.

A 2025 study, based on diabetic retinopathy screening initiatives in rural Punjab, highlights some of the barriers to early detection. The researchers found that patients sometimes declined screening because they believed their eyes were healthy. Mobility limitations, distance from healthcare facilities and transportation difficulties also affected participation. While these findings relate to a specific rural population and cannot be generalised to all Indian patients, they illustrate why awareness of the asymptomatic nature of diabetic eye disease is critical.

Dr. Lalit Verma, Director, Retina Services, Centre For Sight and Former President, AIOS, emphasises the importance of routine screening in identifying retinal changes before they affect vision.

"Diabetic retinopathy is a major complication of diabetes, as retinal damage can progress even without noticeable visual symptoms. Regular retinal screening helps identify early vascular changes, examine the extent of retinal involvement, and understand the most suitable treatment plan. It's crucial to acknowledge that diabetes isn't only about managing blood sugar levels; timely eye checkups should also be promptly prioritized to keep away the risks of vision-threatening complications."

When changes in vision need attention

Although early diabetic retinopathy may not produce noticeable symptoms, certain changes in vision should never be ignored. These include:

●      Gradual or sudden blurring of central vision.

●      Difficulty reading, recognising faces or driving.

●      Fluctuating vision that changes from day to day.

●      Dark spots, floaters or a sudden increase in floaters.

●      Distorted vision or difficulty seeing clearly.

●      Flashes of light or a curtain-like shadow across the field of vision.

Sudden flashes, a sudden increase in floaters or a curtain-like shadow can indicate a serious retinal problem and require urgent ophthalmic assessment.

Routine screening remains essential, even in the absence of these symptoms.

Screening, prevention and timely intervention

Regular eye examinations are an essential part of diabetes management. According to the Indian consensus guidelines developed by the All India Ophthalmological Society (AIOS) and Vitreo-Retinal Society of India (VRSI), people with Type 1 diabetes should undergo an initial comprehensive dilated eye examination within five years of diagnosis, followed by regular annual screening. Those with Type 2 diabetes should have a comprehensive eye examination at the time of diagnosis itself, followed by annual screening.

For individuals already diagnosed with diabetic retinopathy, the frequency of follow-up examinations depends on the severity of the condition. More advanced disease may require more frequent monitoring and intervention as advised by the ophthalmologist.

A comprehensive eye examination allows specialists to assess the retina and identify signs of diabetic damage. Depending on the clinical findings, additional investigations and retinal imaging may be recommended to evaluate the extent of involvement and determine the appropriate course of action.

Alongside regular screening, everyday health management can help reduce the risk of complications. People living with diabetes should:

●      Maintain blood sugar levels within the range recommended by their treating physician.

●      Monitor blood pressure and cholesterol.

●      Follow a balanced diet and maintain regular physical activity.

●      Take prescribed diabetes medication consistently.

●      Avoid smoking.

●      Follow the ophthalmologist's recommended screening, monitoring and treatment schedule, even when vision appears normal.

Treatment depends on the type and stage of diabetic eye disease. Early-stage conditions may require regular monitoring, while diabetic macular oedema and certain cases of proliferative diabetic retinopathy may be treated with intravitreal anti-VEGF injections or laser procedures. Advanced cases involving significant bleeding or tractional retinal detachment may require vitrectomy. With a network of over 95 eye care centres across India and over 30 years of experience in eye care, Centre For Sight provides specialised diabetic eye screening and retinal care. Its services include intravitreal injections, laser procedures and vitreoretinal surgery, with treatment approaches guided by individual clinical assessments and the nature and stage of the condition.

(Prof.) Dr. Mahipal S. Sachdev, Padma Shri Awardee, Chairman and Medical Director at Centre For Sight and Former Professor, AIIMS, believes that eye examinations must become an integral part of routine diabetes care.

"Diabetes often affects the eyes long before you notice any changes in your vision. Silent progression of the condition is among the biggest concerns with diabetic retinopathy, necessitating regular retinal checkups for diabetic individuals. We emphasize that good blood sugar control must go hand in hand with routine eye screening. Early detection enables us to spot retinal changes, monitor disease progression and lay down customized treatment plans before major vision loss occurs. My advice is simple: do not wait for your vision to deteriorate before you decide to get your eyes checked."

Managing diabetes requires looking beyond blood sugar levels. Regular retinal screening and timely intervention are essential to protecting long-term vision. For people living with diabetes, eye examinations should be an integral part of ongoing healthcare, not something to consider only when vision begins to deteriorate.