Key Takeaways
- Age is the most common cause — more than half of Americans have cataracts by age 80
- UV radiation, smoking, and diabetes significantly accelerate cataract development
- Long-term use of corticosteroid medications is a frequently overlooked risk factor
- Cataracts cannot currently be prevented entirely, but lifestyle choices can reduce your risk and slow progression
- Cataract surgery is the only proven treatment for cataracts. It is also one of the safest surgical procedures in medicine.
A cataract forms when proteins in the eye’s natural lens begin to clump together, causing the lens to cloud over and block light from passing clearly to the retina. The result is blurry, dimmed, or distorted vision. It is often described as looking through a fogged windshield or a piece of wax paper.
Cataracts are extremely common and a leading cause of reversible vision loss worldwide. Understanding what causes them, and what increases your personal risk, helps you take steps to protect your vision and know when to seek evaluation.
Learn more about cataract surgery at Berkeley Eye Center →
What Are the Most Common Symptoms of Cataracts?
Cataracts develop slowly and symptoms often go unnoticed in the early stages. Common signs include:
- Blurry, hazy, or cloudy vision
- Colors that appear faded or washed out
- Increased sensitivity to light and glare
- Halos around lights, especially at night
- Difficulty seeing clearly at night or in dim lighting
- Frequent changes in glasses or contact lens prescription
- Double vision in one eye
Patients with advanced cataracts often describe vision as looking through a waterfall or frosted glass. If you notice any of these symptoms, schedule a comprehensive eye exam. Early detection allows for better planning around the timing of surgery.
What Causes Cataracts?
Age: The Most Common Cause
The natural lens of the eye is made primarily of water and protein. Over time, those proteins begin to break down and clump together. This forms the cloudy areas we call cataracts. This is a normal part of aging that affects nearly everyone eventually. According to the American Society of Cataract and Refractive Surgery, more than half of Americans either have a cataract or have had cataract surgery by age 80.
UV Radiation from Sunlight
Long-term exposure to ultraviolet light, particularly UVB rays, accelerates the breakdown of lens proteins. People who spend significant time outdoors without UV-protective eyewear accumulate UV damage over decades. In Houston’s climate, where outdoor exposure is year-round and intense, UV protection is especially relevant. Wearing sunglasses with UV400 protection and a brimmed hat reduces cumulative exposure significantly.
Smoking
Smoking is one of the most well-established modifiable risk factors for cataracts. Smokers are two to three times more likely to develop cataracts than non-smokers. The toxic chemicals in cigarette smoke damage lens proteins directly and reduce antioxidant levels in the eye. Quitting smoking at any age reduces risk.
Diabetes and Blood Sugar
Uncontrolled blood sugar causes chemical changes in the lens that accelerate clouding. Diabetic cataracts often develop earlier and progress more rapidly than age-related cataracts. Managing blood sugar effectively, through diet, medication, or insulin, is one of the most important things a diabetic patient can do for long-term eye health.
Medications: Particularly Corticosteroids
Long-term use of corticosteroid medications (steroids), whether oral, inhaled, topical, or as eye drops, is a frequently overlooked cataract risk factor. Patients who use steroids regularly for conditions like asthma, rheumatoid arthritis, or inflammatory bowel disease have a meaningfully higher risk of developing posterior subcapsular cataracts. If you take steroids long-term, mention this to your eye doctor so they can monitor your lens health.
Eye Injury or Prior Eye Surgery
Trauma to the eye, even minor injuries from years earlier, can damage the lens and trigger cataract formation. Prior eye surgeries, including retinal procedures, also increase risk. Patients who have had LASIK are still candidates for cataract surgery, though precise measurements require advanced technology.
Family History and Genetics
A family history of early-onset cataracts increases your likelihood of developing them earlier than average. While genetics cannot be changed, knowing your family history helps your eye doctor set an appropriate monitoring schedule.
Other Contributing Factors
- Excessive alcohol consumption
- Obesity
- High blood pressure (hypertension)
- Previous radiation therapy to the upper body or head
- Prolonged exposure to very bright light environments (welding, certain industrial settings)
Can You Reduce Your Risk of Cataracts?
You cannot completely prevent cataracts. Age-related lens changes are a normal biological process. But research consistently shows that certain lifestyle habits can reduce your risk or slow progression:
- Wear UV-protective sunglasses outdoors — UV400 rated lenses block the UVA and UVB radiation that accelerates lens damage
- Don’t smoke — and if you do, quitting at any age reduces risk
- Manage diabetes and blood sugar levels through diet, exercise, and medication as directed
- Eat a diet rich in antioxidants — leafy greens, colorful vegetables, and foods high in vitamins C and E support overall eye health
- Limit alcohol consumption
- Get regular comprehensive eye exams — particularly if you have risk factors like diabetes, family history, or long-term steroid use
For a deeper look at reducing your risk, read our full cataract prevention guide.
When Should I See a Doctor About Cataracts?
You should schedule a comprehensive eye exam if you notice any changes in your vision, such as blurring, increased glare, difficulty driving at night, or frequent prescription changes. Cataracts do not have to be “bad enough” before you seek evaluation. Early assessment gives you and your surgeon time to plan the right approach before symptoms significantly affect your daily life. Learn more about when to have cataract surgery.
Most patients are surprised to learn how much their vision can improve with treatment. Read cataract patient testimonials from Berkeley Eye Center.
Frequently Asked Questions About Cataract Causes
Schedule a Cataract Evaluation in Houston
If you have risk factors for cataracts, or have noticed changes in your vision, the first step is a comprehensive eye exam at Berkeley Eye Center. Our board-certified cataract surgeons evaluate lens health, discuss your risk factors, and help you understand your options — whether that’s monitoring, updating your glasses, or planning for surgery.