People with diabetes may be twice as likely to develop cataracts as those without diabetes.

Diabetes affects around 9.4% of the population of the United States.

A person with diabetes who develops cataracts may not notice their symptoms at first. Cataracts are cloudy areas in the lens of the cornea that blur vision.

People can try several treatment options to reduce the severity of cataracts. The only treatment that can remove them completely is surgery.

This article explores the link between cataracts and diabetes and how cataract surgery can help improve vision.

a person with diabetes has cataracts in their blue eyesShare on Pinterest
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Diabetes can cause cataracts for several reasons.

People with diabetes can experience damage to blood vessels in the eyes from high blood sugar and swelling in the liquid between the eyeball and cornea lens.

Blood vessel damage

In people with diabetes, the body produces less insulin than it needs or cannot use insulin properly. Insulin moves sugar, or glucose, from the blood into the cells, where the body uses it as energy.

Without sufficient insulin, glucose cannot enter the cells. It then builds up in the bloodstream, resulting in high blood sugar.

When a person has high blood sugar over a long period, it can damage their blood vessels, including those in the eye. This can increase the likelihood of getting a cataract.

Aqueous humor swelling

Another factor involved in cataracts involves the aqueous humor, which is the liquid that fills the space between the eyeball and the cornea lens.

When glucose levels are high in the aqueous humor, the lens can swell, contributing to blurred vision. A 2021 study on 37 people with diabetes and cataracts found high glucose levels in the aqueous humor. People who had the most difficulty controlling blood sugar had the highest glucose levels in the aqueous humor.

When blood sugar is high for long periods, enzymes in the lens of the cornea convert glucose to sorbitol, which can swell the lens and contribute to blurred vision.

Learn more about the link between diabetes and blurry vision here.

The main risk factors for people with diabetes developing cataracts are older age, long duration of diabetes, and decreased metabolic control.

According to the Centers for Disease Control and Prevention (CDC), 32% of adults aged 45 and over who have diabetes also have cataracts.

People over 65 with diabetes are twice as likely to develop cataracts than people of the same age without diabetes. People under 65 with diabetes are three to four times more likely to develop cataracts than people of the same age who do not have the condition.

Learn about other possible complications of diabetes here.

Cataracts form very slowly. A person can have an early-stage cataract without showing any symptoms.

The main signs and symptoms of a cataract include:

Most people with diabetes should see a doctor for a dilated eye exam once a year. A person might need more regular checkups depending on the type of diabetes in question and how long they have had it.

During an eye exam, a doctor will place drops in the person’s eyes to widen their pupils. Using a magnifying lens, the doctor will examine the large area at the back of the eye. They will also test the person’s vision and the pressure in their eyes. People usually have blurry vision for a few hours after a dilated exam.

If a person notices sudden vision changes, including flashes of light, floaters, or obscured vision, they should call a doctor right away.

There is no way to prevent cataracts from forming, but people with diabetes may lower their risk of developing cataracts by controlling their blood sugar.

Preventative steps include:

Surgery is the only treatment for cataracts. However, for less severe cataracts, it might help a person to:

  • get an altered eyeglass prescription
  • use a brighter light for tasks such as reading
  • add anti-glare coatings to eyeglass lenses

People with less severe cataracts should monitor changes in their vision and follow a regular eye exam schedule.


When cataracts get in the way of doing daily tasks, a doctor will usually recommend surgery.

Cataract surgery is a relatively safe procedure done under local anesthetic. It can take around 1 hour, although some operations may take less time. People can usually go home the same day.

During surgery, a doctor removes the clouded lens and replaces it with a clear, artificial one. The artificial lens, or intraocular lens, requires no care and can significantly restore the eye’s ability to focus. Once a doctor has removed the cataract, it will not grow back.

A doctor can perform two types of surgery to remove a cataract.


The doctor makes a small incision in the side of the cornea and inserts a tiny probe, the same thickness as a human hair. This probe emits ultrasound waves that break up the lens so the doctor can suction it out.

Extracapsular surgery

The doctor makes a slightly larger incision in the cornea to remove the lens core in one piece. They then put the artificial lens in place.

Learn more about what to expect during cataract surgery here.

Following cataract surgery, it can take a few days for a person’s vision to return fully. They will probably have to wear an eye patch for a day or two after surgery. They may also have to use eye drops to reduce inflammation and the chance of infection.

The presence of other eye diseases such as glaucoma or diabetic retinopathy might affect a person’s chances of recovering full vision following surgery.

After surgery, a person may experience temporary, typical symptoms, such as:

  • blurred vision
  • double vision
  • red or bloodshot eye
  • grittiness
  • watering

After 4–6 weeks, these side effects should have disappeared.

According to the National Eye Institute, 90% of people can see better after having cataract surgery.

High blood sugar in people with diabetes makes cataracts more likely to form. Older people, those who have difficulty with glycemic control, and people who have had diabetes for a long time are more likely to develop cataracts.

Surgery to replace a cloudy cataract lens with an artificial lens is simple, has a great success rate, and dramatically improves vision for most people.