Diabetes and Cataracts: How High Blood Sugar Can Cloud Your Vision

Cataracts are often spoken about as a natural part of getting older. For many people, that is true. The clear lens inside the eye slowly becomes cloudy over time, and the world begins to look dimmer, blurrier, or less colourful than it once did.

But aging is not the only reason cataracts form.

For people living with diabetes, cataracts can appear earlier and progress faster. This is because diabetes does not only affect blood sugar. It can affect the small, delicate structures throughout the body, including the eyes.

In June 2025, Trinidad Eye Hospital hosted a live discussion for Cataract Awareness Month on the connection between diabetes and cataracts. The conversation featured Dr. Ronnie Bhola, Vitreo-Retinal Surgeon and CEO of Trinidad Eye Hospital, and Dr. Joel David Teelucksingh, Consultant in Internal Medicine, Endocrinology, and Diabetes. The session was moderated by Prianka Persad, Surgical Services Manager at Trinidad Eye Hospital.

The discussion opened an important window into how diabetes can affect vision, why prevention matters, and what patients can do to protect their sight.

What is a cataract?

Inside the eye is a natural lens. This lens helps focus light so the brain can form a clear picture of the world.

When the lens is healthy, it is clear, almost like clean glass. Light passes through easily. But when a cataract forms, the lens becomes cloudy. The clearer the lens, the clearer the vision. The cloudier the lens, the harder it becomes for light to pass through properly.

Dr. Bhola described a cataract as being “like looking through a dirty window.” That image is simple, but it says a lot. The world is still there. The light is still there. But something is blocking the view.

A person with cataracts may notice cloudy vision, blurry vision, faded colours, glare from bright lights, difficulty seeing at night, or frequent changes in their glasses prescription. Sometimes people describe it as feeling like there is a film over the eye.

What causes cataracts?

The most common cause of cataracts is aging. As the years pass, the proteins in the lens begin to change and clump together. This causes the lens to lose its natural clarity.

However, cataracts can also be linked to other factors, including diabetes, eye injury, eye inflammation, long-term steroid use, smoking, obesity, and too much exposure to sunlight without proper eye protection.

Some cataracts can also be present from birth, although this is less common.

This is why cataracts should not be seen as “just an old person’s problem.” While they are more common with age, certain health conditions can invite them earlier.

Are people with diabetes more likely to get cataracts?

Yes. People with diabetes are more likely to develop cataracts at a younger age, and cataracts may progress faster in people with poorly controlled blood sugar.

To understand why, it helps to think of the eye as a small, living camera. The lens is not just a piece of glass sitting inside the eye. It is living tissue, and it is affected by the environment around it.

When blood sugar levels remain high, extra glucose can enter the lens. Inside the lens, some of that glucose is converted into a substance called sorbitol. Sorbitol can draw water into the lens, causing swelling and stress within the lens fibres. Over time, this can damage the lens and contribute to cloudiness.

In simple terms, too much sugar in the bloodstream can slowly disturb the clear structure of the lens. Like sugar water drying on a clean window, it can leave behind changes that make the view less clear.

Photo by Tessy Agbonome: https://www.pexels.com/photo/doctor-hands-holding-glucose-meter-19963068/

Why blood sugar control matters

Diabetes is not only about one high reading. It is about patterns.

A person may check their blood sugar at one moment and get one result, but doctors often use HbA1c to understand the bigger picture. HbA1c gives an idea of a person’s average blood sugar over the past three months.

During the discussion, Dr. Teelucksingh explained that keeping HbA1c within a healthy target range can reduce the chance of complications affecting the eyes. This matters because the eyes are filled with tiny, sensitive structures. They do not respond well to years of sugar levels swinging too high or too often.

High blood sugar can contribute to cataracts, but it can also affect the retina, the light-sensitive layer at the back of the eye. This is called diabetic retinopathy, and it is one of the most serious diabetes-related eye conditions.

So when a person with diabetes protects their blood sugar, they are not only protecting themselves from cataracts. They are also protecting the deeper parts of the eye that help make vision possible.

Can pre-diabetes affect the eyes too?

Pre-diabetes is sometimes treated casually, as though it is not serious because it is not “full diabetes.” But pre-diabetes is a warning light.

It means the body is already struggling to manage blood sugar properly. Dr. Teelucksingh referred to this stage as “trouble brewing.” That phrase is useful because it reminds patients that changes may already be starting quietly inside the body.

The good news is that pre-diabetes can often be improved or even reversed through lifestyle changes. Healthier eating, regular movement, weight management, and monitoring blood sugar, blood pressure, and cholesterol can make a real difference.

Pre-diabetes is not a sentence. It is a signal. It is the body asking for attention before greater damage is done.

How often should people with diabetes check their eyes?

People with diabetes should not wait until their vision changes before getting an eye exam.

This is one of the most important lessons from the discussion. By the time vision becomes blurry, diabetic eye disease may already be present. In some cases, early changes can happen quietly.

Dr. Bhola explained that newly diagnosed diabetic patients should have their eyes screened. If no diabetic eye disease is found, they may usually be placed on a yearly follow-up. If early changes are seen, the patient may need to be reviewed sooner, sometimes within three to six months.

This is why regular eye screening is so powerful. It allows doctors to see what the patient cannot yet feel.

An eye exam is not only about checking whether someone needs glasses. For a person with diabetes, it is also a way of checking the health of the blood vessels, retina, lens, and other parts of the eye.

Can cataracts be treated with drops, honey, or bush medicine?

Many people look for natural ways to treat cataracts. In Trinidad and Tobago, it is not unusual to hear about home remedies, honey, bush medicine, or eye drops that claim to clear cataracts.

But once a cataract has formed, there is currently no proven drop, medicine, or home remedy that can make it disappear.

A cataract is a physical clouding of the lens. Once the lens has become cloudy enough to affect vision, the effective treatment is cataract surgery.

This does not mean patients should panic. Cataract surgery is one of the most common and successful surgeries performed around the world. The cloudy natural lens is removed and replaced with a clear artificial lens, allowing light to pass through again.

For many patients, cataract surgery does more than improve sight. It restores confidence, independence, and the ability to enjoy daily life.

Is cataract surgery safe for people with diabetes?

Cataract surgery can be safe and effective for people with diabetes, but preparation is important.

Modern cataract surgery is far more advanced than it was many years ago. Small incisions are used, the cloudy lens is removed, and an artificial lens is placed inside the eye. The procedure is usually quick, and recovery is often smooth.

However, people with diabetes need careful assessment before surgery. This is because diabetes may already be affecting other parts of the eye, especially the retina. If diabetic retinopathy or macular swelling is present, the doctor may need to manage those conditions before or around the time of cataract surgery.

Patients may also be advised to improve blood sugar control, manage blood pressure, stop smoking, take medications as prescribed, and follow their doctors’ instructions closely.

Cataract surgery is not only about the eye. For a diabetic patient, it is about preparing the whole body so the eye has the best chance to heal well.

Dr. Bhola examines a patient's eyes at his clinic

How can people with diabetes reduce their risk of cataracts?

Not every cataract can be prevented, especially those related to aging. But people can lower their risk of developing cataracts earlier or allowing them to progress faster.

The first step is controlling blood sugar. When sugar levels are better managed, there is less stress on the lens and other parts of the eye.

The second step is regular eye screening. A person with diabetes should know the condition of their eyes before symptoms appear.

Other helpful steps include managing blood pressure and cholesterol, avoiding smoking, wearing UV-tested sunglasses outdoors, staying physically active, and eating more foods that support overall health.

Dr. Bhola spoke about the importance of choice, especially around food and movement. This is not always easy. Healthy food can be expensive. Life can be busy. Stress, work, family responsibilities, and cultural habits all shape how people eat and live.

But the goal is not perfection. The goal is to make more protective choices, more often.

A walk after dinner. A smaller portion of white rice. More vegetables on the plate. Taking medication on time. Booking the eye exam that has been postponed. These small choices may look ordinary, but over time, they help protect something precious.

Why this matters for families

Diabetes is not only an individual health issue. It affects families, workplaces, communities, and the healthcare system.

When someone loses vision, their independence can change. Simple things like driving, cooking, reading, working, or recognizing faces can become harder. This is why protecting vision is also about protecting quality of life.

During the discussion, Dr. Teelucksingh reminded viewers that diabetes and obesity are being seen at younger ages, even in children. That means the habits formed in the home matter. What children eat, how much they move, how much sleep they get, and what they see adults doing can shape their future health.

Prevention is not only for people who already have diabetes. It is for families who want to build a healthier future.

The clearer path forward

Diabetes and cataracts are connected, but the story does not have to end in vision loss.

The lens of the eye may be small, but it teaches a big lesson. The body remembers how it is treated. High blood sugar, over time, can leave its mark. But care, prevention, and early treatment can also leave their mark.

Cataracts can be treated. Diabetic eye disease can often be detected early. Blood sugar can be managed. Pre-diabetes can sometimes be reversed. And vision can be protected when patients take action before the window becomes too cloudy.

The message is simple and worth repeating: do not wait for blurry vision to begin caring for your eyes.

For people living with diabetes, regular eye exams are not optional extras. They are part of protecting the life they want to keep seeing clearly.

Your eyes are more than windows to the world. They are windows into your health. Take care of them early, and they can help you keep seeing the moments that matter.