[Signs, symptoms, and clinical forms of cataract in adults]

Cataract is a partial or total opacification of the crystalline lens. In adults, cataract is acquired; the most common form is the age-related cataract. Assessment of the functional impact of a cataract is clinical. The common symptom is loss of visual acuity, but other symptoms (photophobia, monocular diplopia, myopic shift, change in color vision, etc.) may be found depending on the anatomical distribution of the opacities (nuclear, posterior subcapsular, cortical). Diagnosis is based on slit-lamp examination after pupillary dilation. This allows classification of the opacities according to their anatomical distribution and can help direct any etiologic work-up. A number of potential causes should be ruled out before concluding that a cataract is age-related. Cataracts may be iatrogenic, associated with other ocular or systemic disease, or induced by ocular trauma. Knowledge of the signs, symptoms, and clinical forms of cataract helps to establish proper indications for cataract surgery in accordance with preferred practice patterns in ophthalmology.