Yes, diabetes significantly raises your risk of developing cataracts, often at a younger age than people without diabetes
High blood sugar from diabetes damages the lens of your eye over time. When glucose levels stay elevated, sugar builds up inside the lens and draws in fluid, causing the lens to swell and become cloudy. This cloudiness is a cataract. People with diabetes can develop cataracts in their 40s or 50s, whereas cataracts typically appear in people without diabetes after age 60.
The longer you have diabetes and the less controlled your blood sugar is, the higher your risk. Type 1 diabetes carries a particularly high risk because it often develops in childhood, giving decades for damage to accumulate. Type 2 diabetes also raises cataract risk, though it may develop more slowly since the condition often starts later in life.
Key Takeaways
- High blood sugar causes sugar to accumulate in the eye lens, making it swell and turn cloudy.
- People with diabetes can develop cataracts 10 to 20 years earlier than people without diabetes.
- Keeping your blood sugar as close to normal as possible slows or prevents cataract formation.
- Regular eye exams can catch early cataracts before they affect your vision.
- Cataract surgery is the only treatment once the lens becomes too cloudy, but it is highly effective.
How blood sugar damage creates cataracts
The lens sits behind the colored part of your eye and focuses light onto the back of the eye so you can see clearly. It is made mostly of water and protein arranged in a precise pattern. When blood sugar is high, glucose enters the lens and is converted to a substance called sorbitol through a chemical pathway in your body.
Sorbitol cannot leave the lens easily, so it accumulates and pulls water in with it. The lens swells, its proteins clump together, and light cannot pass through clearly anymore. This clouding happens gradually—you may not notice it at first, but over months or years the cloudiness increases and your vision becomes blurry or dim.
Some people with poorly controlled diabetes develop cataracts so quickly that the process is noticeable within weeks or months. This rapid form is less common but can happen when blood sugar stays very high for extended periods.
Your risk depends on how long you have had diabetes and how well controlled it is
Two main factors determine whether you will develop cataracts: how many years you have had diabetes, and how close your blood sugar has stayed to normal. Someone diagnosed with type 1 diabetes at age 10 faces a much higher lifetime risk than someone diagnosed with type 2 diabetes at age 60, simply because the damage has more time to accumulate.
Blood sugar control matters just as much. If your average blood sugar (measured by a test called hemoglobin A1C) stays above 8 percent, your cataract risk rises significantly compared to someone who keeps it below 7 percent. The difference between good control and poor control can be years or even decades in when cataracts appear.
Other factors also play a role: smoking speeds up cataract formation, as does prolonged sun exposure without eye protection. If you have high blood pressure or high cholesterol along with diabetes, your risk increases further.
What to watch for in your own vision
Early cataracts often cause no symptoms. You might not realize anything is wrong until an eye doctor points it out during a routine exam. As the cataract grows, you may notice your vision becoming gradually blurrier or dimmer, as if you are looking through frosted glass. Colors may appear faded or yellowed.
Some people experience glare or halos around lights, especially at night. You might find that you need a brighter light to read, or that your glasses prescription keeps changing. These changes happen slowly enough that you may adjust without realizing it—a family member or friend might notice the change before you do.
If you have diabetes, do not wait for symptoms to appear. Regular eye exams are the best way to catch cataracts early, when they are still small and not affecting your daily life.
How to reduce your cataract risk
The most important step is keeping your blood sugar as close to normal as possible. Work with your doctor to set a target A1C level and adjust your medications, diet, and exercise to reach it. Even small improvements in blood sugar control make a measurable difference in cataract risk over time.
Protect your eyes from the sun by wearing sunglasses that block ultraviolet (UV) light whenever you are outside for extended periods. UV exposure accelerates cataract formation in people with diabetes. A wide-brimmed hat provides additional protection.
If you smoke, stopping reduces your cataract risk. Smoking roughly doubles the speed at which cataracts develop in people with diabetes. Your eye doctor can also discuss whether any of your current medications have side effects that affect eye health.
Keep your blood pressure and cholesterol in the ranges your doctor recommends, since both conditions interact with diabetes to increase cataract risk. Regular eye exams—at least once a year if you have diabetes—allow your eye doctor to monitor your lens and catch changes early.
What happens if a cataract develops
If an eye exam shows a cataract, your eye doctor will monitor it over time to see how quickly it grows. Many cataracts develop slowly and may never interfere with your daily activities. You might not need treatment for years, or ever. Your doctor will discuss whether your vision is affected enough to consider surgery.
Cataract surgery is the only treatment that removes the cloudiness. The surgeon removes the cloudy lens and replaces it with a clear artificial lens. The procedure takes about 15 minutes, is done under local anesthesia (numbing drops), and has a high success rate. Most people see significant improvement in vision within a few days.
You do not have to rush into surgery. Many people live comfortably with a small cataract for years. Surgery becomes worth considering when the cataract makes it hard to drive, read, or do activities you care about. Your eye doctor can help you decide the right timing.
Diabetes increases cataract risk in both eyes
Cataracts from diabetes typically develop in both eyes, though one may progress faster than the other. If you have a cataract in one eye, there is a high likelihood that a cataract will develop in the other eye as well, usually within a few years.
If you need surgery on one eye, your doctor will monitor the other eye closely. Some people have surgery on both eyes at different times—usually waiting at least a week or two between procedures so one eye heals before the other is operated on. This approach lets you maintain vision in at least one eye throughout recovery.
Frequently Asked Questions
Can I reverse a cataract by controlling my blood sugar better?
No. Once the lens proteins have clumped together and become cloudy, lowering your blood sugar will not clear the cloudiness. However, better blood sugar control will slow or stop the cataract from getting worse, and may prevent cataracts from developing in the other eye or later in life.
How often should I have my eyes checked if I have diabetes?
Most eye doctors recommend at least one exam per year for people with diabetes. If you already have a cataract or other eye problems, your doctor may want to see you more often. Ask your eye doctor what schedule is right for your situation.
Will cataract surgery affect my diabetes management?
Cataract surgery does not change how you manage your diabetes. You will continue taking your diabetes medications as usual. After surgery, you will use antibiotic and anti-inflammatory eye drops for a few weeks, but these do not interfere with diabetes treatment.
If I have diabetes in only one eye, can I still get cataracts?
This is not possible. Diabetes is a whole-body condition affecting both eyes equally. If you have been told you have diabetes in only one eye, that is likely a misunderstanding—your eye doctor may have been referring to complications in one eye, but the diabetes itself affects both.
What is the difference between a cataract from diabetes and a regular age-related cataract?
The cloudiness looks the same under a microscope, but diabetes-related cataracts develop much earlier in life and can progress faster. The underlying cause is the same—protein damage in the lens—but high blood sugar accelerates the process. Treatment is identical regardless of the cause.