Cataract is the presence of opacity in the crystalline lens that causes painless, progressive blurring of vision
Leading cause of blindness worldwide and the most prevalent ocular disease
Mechanism of cataract formation is multifactorial
Chronic and age-related
Etiology
Initiating events that lead to loss of transparency of both the cortical and nuclear lens tissue is the oxidation of the membrane lipids, structural or enzymatic proteins or DNA by peroxidases or free radicals induced by ultraviolet (UV) light
Risk Factors
Increasing age
UV radiation - ultraviolet B (UVB) cumulative lifetime exposure
Diabetes mellitus, hypertension, high body mass index
Drugs (eg long-term topical, systemic or inhaled corticosteroids, Phenothiazine, Chlorpromazine)
Smoking
Drinking excessive amounts of alcohol
Gender - females are most likely to have cataract and progress to blindness
Nutrition - low antioxidant levels is associated with increased risk of cataract formation
Obesity
Dehydration/diarrheal crises
Genetics in age-related cataract cases (eg cortical cataracts and nuclear cataracts)
Prior intraocular surgery
Moderate to high myopia
Exposure to ionizing radiation (eg chest x-ray, radiation therapy)
Ocular trauma
Signs and Symptoms
Decreased vision and increased problems with glare are the hallmark symptoms
Increased nearsightedness called "myopic shift" before opacity of the lens occur
