A 62-year-old man presents with progressive painless vision loss over 3 years. Slit-lamp examination reveals a lens opacity that begins at the periphery and progresses centripetally, with a characteristic brown discoloration at the nucleus. Which type of cataract is most common in this age group?

Explanation

## Most Common Age-Related Cataract Type **Key Point:** Nuclear sclerotic cataract is the most common type of age-related cataract, accounting for approximately 50% of all senile cataracts. ### Clinical Presentation of Nuclear Sclerotic Cataract - **Onset:** Typically after age 50–60 years - **Location:** Begins in the nucleus and progresses centripetally - **Appearance:** Brown or amber discoloration of the nucleus (brunescence) - **Progression:** Slow and insidious over years - **Associated symptom:** Myopic shift in early stages ("second sight") ### Pathophysiology Nuclear sclerosis results from: 1. Accumulation of lens proteins and cross-linking 2. Increased lens density and refractive index 3. Loss of lens elasticity (presbyopia) 4. Oxidative damage to lens crystallins ### Comparison with Other Cataract Types | Feature | Nuclear Sclerotic | Cortical | Posterior Subcapsular | Traumatic | |---------|-------------------|----------|----------------------|-----------| | **Most common age** | >60 years | >60 years | 50–60 years | Any age | | **Location** | Nucleus | Cortex | Posterior capsule | Variable | | **Onset** | Slow | Slow | Rapid | Acute | | **Frequency** | ~50% of senile | ~35% of senile | ~15% of senile | <5% | | **Brunescence** | Yes | No | No | No | **High-Yield:** In an elderly Indian patient with age-related cataract, nuclear sclerotic type should be your first thought — it is the most prevalent form encountered in clinical practice and in NEET PG exams. **Clinical Pearl:** The myopic shift seen in early nuclear sclerosis can temporarily improve near vision in presbyopic patients, leading them to delay seeking treatment ("second sight phenomenon"). ### Why This Is the Correct Answer Nuclear sclerotic cataract is the most frequent age-related cataract type globally and in India, with a well-established epidemiology. The clinical presentation described — peripheral opacity progressing inward with nuclear browning — is pathognomonic for this type.