Cataracts
What Are Cataracts?
A cataract is a clouding of the eye’s natural lens that causes vision to become blurry, hazy, or less clear over time. The lens is located behind the colored part of the eye (the iris) and helps focus light onto the retina, allowing you to see sharp, detailed images. When the normally clear lens becomes cloudy, light is scattered instead of passing cleanly through the eye, leading to progressive vision changes.
Cataracts are one of the most common eye conditions and are a leading cause of reversible vision loss worldwide. Although they most often develop as part of the natural aging process, cataracts can also occur as a result of eye injuries, certain medications, medical conditions, or, less commonly, be present at birth.
Most cataracts develop gradually, and many people may not notice symptoms in the early stages. Regular comprehensive eye examinations are important for detecting cataracts and monitoring changes in vision over time.
Types of Cataracts
01
Nuclear Cataracts
Nuclear cataracts form in the center (nucleus) of the lens and are the most common type associated with aging. As they progress, the lens may become yellow or brown, making colors appear less vibrant. Early nuclear cataracts may temporarily improve near vision, a phenomenon sometimes called “second sight,” before vision gradually worsens.
02
Cortical Cataracts
Cortical cataracts develop in the outer portion of the lens and often appear as white, wedge-shaped spokes that extend toward the center. They commonly cause glare, reduced contrast sensitivity, and difficulty seeing in bright lighting or at night.
03
Posterior Subcapsular Cataracts
Posterior subcapsular cataracts develop near the back surface of the lens. They often progress more quickly than other cataract types and can significantly affect reading vision, cause glare around lights, and reduce vision in bright environments. They are more commonly associated with diabetes, long-term corticosteroid use, chronic eye inflammation, and previous eye surgery.
Symptoms of Cataracts
Symptoms often develop slowly and may become more noticeable over time.
Common signs include:
- Blurred or cloudy vision
- Difficulty seeing at night
- Increased sensitivity to sunlight or bright lights
- Glare or halos around headlights
- Faded or yellowed color perception
- Frequent changes in eyeglass or contact lens prescriptions
- Double vision in one eye
- Difficulty reading despite updated glasses
- Needing brighter light for close work
- Reduced contrast sensitivity, making it harder to distinguish objects from their background
The severity of symptoms varies depending on the location and density of the cataract.
What Causes Cataracts?
The most common cause of cataracts is age-related changes within the natural lens. Over time, proteins that help maintain lens clarity begin to break down and cluster together, reducing the lens’s transparency.
Other factors that may contribute to cataract development include:
- Aging
- Diabetes mellitus
- Long-term corticosteroid use
- Previous eye injury or trauma
- Chronic inflammation inside the eye (uveitis)
- Previous eye surgery
- Smoking
- Excessive ultraviolet (UV) light exposure
- Radiation exposure
- Certain inherited genetic conditions
- Family history of cataracts
Although aging cannot be prevented, maintaining good overall health and protecting your eyes from excessive UV exposure may help reduce certain risk factors.
Who Is at Risk?
While anyone can develop cataracts, the likelihood increases with age.
You may have an increased risk if you:
- Are over the age of 60
- Have diabetes
- Use corticosteroid medications for an extended period
- Smoke cigarettes
- Have experienced significant eye trauma
- Have a family history of cataracts
- Spend prolonged time outdoors without UV-protective eyewear
- Have a history of chronic eye inflammation
Not everyone with these risk factors will develop cataracts, and some individuals develop cataracts without any identifiable risk factors beyond normal aging.
How Are Cataracts Diagnosed?
Cataracts are diagnosed during a comprehensive ophthalmic examination.
Your ophthalmologist will evaluate both your vision and the health of your eyes using specialized instruments. A comprehensive evaluation may include:
- Best-corrected visual acuity testing
- Refraction to determine whether changes in glasses improve vision
- Slit-lamp biomicroscopy to examine the lens in detail
- Dilated examination of the retina and optic nerve
- Measurement of intraocular pressure when appropriate
Your ophthalmologist will also determine whether another eye condition—such as glaucoma, macular degeneration, diabetic retinopathy, or corneal disease—may be contributing to your symptoms.
Can Cataracts Be Prevented?
There is no proven way to completely prevent age-related cataracts. However, healthy lifestyle choices may help reduce certain risk factors and support long-term eye health.
These include:
- Wearing sunglasses that block 100% of UVA and UVB rays
- Using a wide-brimmed hat outdoors
- Managing diabetes and other chronic medical conditions
- Avoiding smoking
- Eating a balanced diet rich in fruits and leafy green vegetables
- Scheduling routine comprehensive eye examinations
Because cataracts typically develop gradually, regular eye exams are often the best way to detect changes before they significantly affect daily life.
When Should You See an Ophthalmologist?
You should schedule a comprehensive eye examination if you notice:
- Gradually worsening blurry vision
- Increasing difficulty driving at night
- Glare or halos around lights
- Frequent changes in your glasses prescription
- Colors appearing faded
- Vision changes that interfere with reading, work, hobbies, or everyday activities
Even if your vision seems normal, routine comprehensive eye examinations are important for detecting cataracts and other eye diseases before they begin affecting your sight.
Frequently Asked Questions
Yes. Most cataracts are age-related and develop gradually over many years. However, cataracts can also occur in younger individuals due to injury, certain medications, or underlying medical conditions.
If left untreated, advanced cataracts can lead to severe vision impairment and remain one of the leading causes of reversible blindness worldwide.
No. While updating your eyeglass prescription may improve vision in the early stages, glasses cannot eliminate the clouding within the natural lens.
Age-related cataracts commonly develop in both eyes, although they often progress at different rates.
Progression varies from person to person. Some cataracts remain stable for years, while others progress more rapidly depending on the type of cataract and individual risk factors.
