Differentiating cataracts

	Subcapsular			Nuclear	Cortical
	Anterior		Posterior
Location	Lies directly under lens capsule		Lies just infront of posterior capsule	Starts as exaggeration of normal ageing involving the lens capsule	May develop ant. Post. or equatorial cortex
Association	Associated with fibrous metaplasia of lens epithelium			Often associated with increased myopia due to increase in RI of nucleus and with spherical aberration.	The opacities starts as clefts and vacuoles b/w the lens fibres due hydration of cortex.
Visual acuity	More effect on VA than nuclear and cortical and more NV problem than DV			Near vision better “Second sight”	Pt. frequently complain of glare (due to scattering of light)
Presentation				Characterized in its early stage by a yellowish blue hue due to diposition of urochrome pigment.	Subsequent opacification result in typical cuneiform(wedge-shaped) or radial spoke-like opacities often in inferonasal quadrant
		Manifest as vacuolated,granular or plaque-like appearance in   SL oblique illumination		Best assessed in SL oblique illumination
		Appears black on retroillumination		Not seen by retroillumination