• Any type of ocular trauma

• Chronic or recurrent uveitis

• Chronic or recurrent uveitis

• Ocular trauma

• Cataracts are classified according to age at onset (congenital, juvenile, senile), cause (e.g., hereditary; secondary to uveitis, trauma, metabolic disease), or location within the lens (anterior polar, anterior subcapsular, anterior cortical, equatorial, peripheral cortical, nuclear, posterior cortical, posterior subcapsular, and posterior polar).

• Congenital cataracts may be unilateral or bilateral, and they may be focal or diffuse (Figures 1 and 2). Focal opacities involving the anterior or posterior suture lines are often nonprogressive, but progression does occur in some cases. A nuclear cataract may appear as a ringlike opacity, a hollow sphere, or a solid opacity in the center (nucleus) of the affected lens. These cataracts rarely progress and often decrease in size relative to total lens size as new layers of normal cortical fiber are produced throughout life. The location, density, and size of a focal cataract determine its effect on vision.