1) By cause

• Congenital cataract (present at birth or early infancy)
• Acquired cataract (develops later)

2) Common acquired (age-related) morphological types

• Subcapsular cataract
  • Anterior subcapsular
  • Posterior subcapsular (often causes glare, worse in bright light/near tasks)
• Nuclear sclerotic cataract
  • Central lens nucleus hardening/yellow-browning
• Cortical cataract
  • Peripheral spoke-like/wedge opacities
• Christmas tree cataract
  • Polychromatic needle-like crystals (less common)

3) By stage of maturity

• Immature cataract: lens partly opaque
• Mature cataract: lens fully opaque
• Hypermature cataract: shrunken/wrinkled capsule
• Morgagnian cataract: hypermature lens with liquefied cortex and sunken nucleus

4) Other etiologic clinical categories

• Secondary (complicated) cataract due to ocular disease (e.g., chronic uveitis)
• Drug-induced cataract (classically steroid-related, often posterior subcapsular)
• Traumatic cataract (penetrating/blunt/electrical/radiation)