Here is something I want every diabetic patient to hear clearly: diabetes does not just affect your blood sugar — it attacks your eyes. Silently. Gradually. And often without any warning until significant damage has already been done.

I have seen patients with type 2 diabetes who felt their vision was perfectly fine — only to discover during a routine retinal examination that they had already lost significant vision in one eye without realising it. By the time they noticed something was wrong, the window for the most effective treatment had narrowed considerably.

If you have diabetes — Type 1 or Type 2 — this blog is one of the most important things you can read today. I want to explain exactly what diabetic retinopathy is, how it progresses, what symptoms to watch for, and why early detection and treatment can genuinely save your sight.

What Is Diabetic Retinopathy?

Diabetic retinopathy is a serious eye complication of diabetes that damages the blood vessels in the retina — the thin, light-sensitive layer at the back of your eye that converts what you see into signals your brain can interpret. Think of the retina as the film in a camera. Without it functioning properly, you simply cannot see.

When blood sugar levels remain consistently high over time, the delicate blood vessels that supply the retina are gradually damaged. They may swell, leak fluid, or bleed. In advanced stages, abnormal new blood vessels grow on the retina — a process called neovascularisation — which are fragile and prone to bleeding, causing severe and potentially permanent vision loss.

Diabetic retinopathy is one of the leading causes of blindness in working-age adults worldwide. In India, where diabetes rates are alarmingly high, the scale of this problem cannot be overstated.

The Four Stages of Diabetic Retinopathy

Understanding how diabetic retinopathy progresses is important because treatment is most effective in the earlier stages — before vision loss occurs.

Stage 1: Mild Non-Proliferative Retinopathy

Tiny balloon-like swellings called microaneurysms appear in the blood vessels of the retina. This is the earliest sign of the disease. At this stage, you will notice absolutely nothing wrong with your vision — which is exactly why it is so dangerous if left undetected.

Stage 2: Moderate Non-Proliferative Retinopathy

More blood vessels are affected and begin to swell. They may lose their ability to transport blood properly. Deposits called hard exudates may form in the retina as fluid leaks out of damaged vessels. Vision may still appear normal at this stage.

Stage 3: Severe Non-Proliferative Retinopathy

Many more blood vessels become blocked, depriving large areas of the retina of their blood supply. The retina sends distress signals to the body to grow new blood vessels to compensate. This is a critical turning point — the disease is about to become significantly more dangerous.

Stage 4: Proliferative Diabetic Retinopathy (PDR)

This is the advanced and most dangerous stage. Abnormal new blood vessels grow on the retina and into the vitreous gel inside the eye. These fragile vessels bleed easily, causing sudden vision loss. Scar tissue can also form and pull the retina away — a condition called tractional retinal detachment — which can cause permanent blindness if not treated urgently.

Diabetic Macular Oedema: The Other Sight-Threatening Complication

Alongside these four stages, diabetic patients can also develop diabetic macular oedema (DME) — a build-up of fluid in the macula, the central part of the retina responsible for sharp, detailed vision used in reading and recognising faces. DME can occur at any stage of diabetic retinopathy and is one of the most common causes of vision impairment in diabetic patients.

Why Diabetic Retinopathy Is So Dangerous

The most alarming characteristic of diabetic retinopathy is that it causes no pain and no noticeable symptoms in its early stages. You can be losing your retinal function for months or years without feeling anything or noticing any change in your day-to-day vision.

By the time symptoms appear — blurred vision, dark spots, floaters, sudden vision loss — the disease has often already progressed to an advanced stage where treatment becomes significantly more complex.

This is why I cannot stress this enough: every diabetic patient needs a dilated retinal examination at least once a year — even if their vision feels perfectly fine. This single habit can genuinely be the difference between preserving your sight and losing it.

Symptoms You Should Never Ignore

While early-stage diabetic retinopathy may be symptom-free, the following signs indicate that the disease has progressed and you need to see an eye specialist immediately:

Blurred or fluctuating vision that comes and goes
Dark spots, floaters, or strings drifting across your field of vision
Difficulty seeing in low light or at night
A dark or empty area in the centre of your vision
Sudden, severe loss of vision in one or both eyes
Colours appearing washed out or faded

Any one of these symptoms in a diabetic patient is a medical urgency. Do not wait for your next scheduled appointment — seek care immediately.

Who Is at Risk of Diabetic Retinopathy?

All diabetic patients are at risk, but some are at significantly higher risk:

People who have had diabetes for more than 5 years
Patients with poorly controlled blood sugar (high HbA1c levels)
Those with high blood pressure or high cholesterol alongside diabetes
Pregnant women with diabetes — pregnancy can accelerate retinopathy progression
Patients with kidney disease alongside diabetes
Smokers with diabetes — smoking significantly worsens blood vessel damage

Treatment for Diabetic Retinopathy in Karnal

The good news is that when diabetic retinopathy is caught early, treatment is highly effective. At Dr Rishi Eye Institute’s diabetic retinopathy clinic in Karnal, treatment is tailored to the stage of the disease:

Early Stage: Monitoring and Diabetes Control

In the early stages, the most powerful treatment is strict control of blood sugar, blood pressure, and cholesterol — alongside regular retinal monitoring every 3 to 6 months.

Laser Photocoagulation

A laser is used to treat leaking blood vessels and reduce the growth of abnormal new vessels. This is a well-established and effective procedure for moderate to severe retinopathy. It does not restore lost vision but prevents further deterioration.

Anti-VEGF Injections

Anti-VEGF injections are given directly into the eye to stop the growth of abnormal blood vessels and reduce macular oedema. These injections have revolutionised the treatment of diabetic macular oedema and are now among the most effective tools available.

Vitrectomy Surgery

In advanced cases with vitreous haemorrhage or tractional retinal detachment, vitrectomy surgery is performed. You can read more about retinal detachment treatment on our dedicated page.

How to Protect Your Eyes If You Have Diabetes

Control your blood sugar as tightly as your doctor advises — HbA1c below 7% is the standard target
Manage blood pressure and cholesterol alongside diabetes
Get a dilated retinal examination every year — or every 6 months if you already have any signs of retinopathy
Stop smoking — the impact on blood vessel health is significant
Report any change in vision to your eye doctor immediately
Never skip your retinal check-up even when your vision feels normal

If you also have glaucoma or are at risk, it is worth knowing that diabetes increases your glaucoma risk too. You can learn more about glaucoma and its connection to diabetes on our glaucoma page.

Do Not Let Diabetes Take Your Sight — Act Now

Diabetic retinopathy is preventable in many cases and treatable in most — but only when caught in time. The tragedy I see in my clinic is not patients who came too early. It is patients who came too late, who had years of retinal damage accumulating silently while they felt their vision was fine.

If you have diabetes and have not had a retinal examination in the last year, please book one today. Not next month. Today. Your retina cannot send you a pain signal — a retinal examination is the only way to know, and it could be the most important eye appointment you ever make.

Book your diabetic eye examination at Dr Rishi Eye Institute, Karnal — open 7 days a week, walk-ins always welcome.

Diabetic Retinopathy: How Diabetes Destroys Your Vision