What Causes Cataracts and its types

What Causes Cataracts?

Cataracts develop when the natural lens of the eye becomes cloudy, preventing light from passing through clearly. This clouding occurs when proteins in the lens break down and clump together, forming opacities that reduce vision.

While cataracts are often associated with aging, several factors can contribute to their early development:

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Common Causes of Cataracts

1. Aging (Age-Related Cataracts)
   The most common cause. As you age, the proteins in your lens gradually break down, leading to clouding and blurred vision — typically starting in your 40s or 50s, and worsening over time.

2. Diabetes
   High blood sugar can accelerate changes in the lens, leading to earlier cataract formation and faster progression.

3. Prolonged UV Exposure
   Long-term exposure to sunlight’s ultraviolet (UV) rays can damage proteins in the lens, increasing cataract risk.

4. Smoking & Alcohol Use
   Smoking and excessive alcohol intake produce oxidative stress, damaging the lens and raising cataract risk.

5. Eye Injuries or Surgeries
   Trauma to the eye or certain types of eye surgery can cause what’s known as traumatic cataracts.

6. Certain Medications
   Long-term use of steroids (especially corticosteroids) is linked to the development of posterior subcapsular cataracts.

7. Genetic Predisposition
   Some people inherit a tendency to develop cataracts early in life or even at birth (congenital cataracts).

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Types of Cataracts

Cataracts are classified based on where they form on the lens and why they develop. Understanding the type helps determine symptoms, progression, and the best treatment plan.

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1. Nuclear Cataracts (Nuclear Sclerosis)

These form in the center (nucleus) of the lens and are usually age-related.

• Symptoms: Gradual blurring, yellowing of vision, or sometimes a temporary improvement in near vision (“second sight”) before it worsens.

• Progression: Develops slowly over years.

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2. Cortical Cataracts

These start at the edges (cortex) of the lens and move inward like spokes on a wheel.

• Symptoms: Glare, light sensitivity, halos, and problems with contrast — especially at night.

• Common in: Diabetics and those with high sun exposure.

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3. Posterior Subcapsular Cataracts

These form at the back of the lens, just beneath the capsule that holds the lens in place.

• Symptoms: Difficulty seeing in bright light, glare, and trouble reading or seeing clearly in daylight.

• Progression: Develops faster than other types — often in younger people, especially those using steroids or with diabetes.

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4. Congenital Cataracts

Present at birth or developed in infancy, often due to genetic disorders, infections during pregnancy (like rubella), or metabolic diseases.

• Symptoms: May not be noticeable at first, but can affect visual development if not treated early.

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5. Traumatic Cataracts

Caused by eye injury, even years before symptoms appear.

• Common in: Individuals with a history of sports injuries or blunt trauma to the eye.

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6. Secondary Cataracts

These develop as a side effect of other medical conditions (like glaucoma or diabetes), or after eye surgeries, such as for retinal problems.
Note: Sometimes people develop a “secondary cataract” (posterior capsule opacification) after surgery, which can be quickly treated with a laser (YAG capsulotomy).

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Conclusion

Cataracts can take many forms and stem from various causes — but the good news is, all types are treatable, and surgery often leads to restored, crystal-clear vision. The key is early detection and personalized care.