Cataract

A cataract is a cloudy area in the lens of the eye that impairs vision. How fast a cataract develops depends on the type and one or both eyes may be affected by the condition. Symptoms may include faded colors, blurry or double vision, halos around light, trouble with bright lights, and difficulty seeing at night. This may result in difficulty driving, loss of independence, and decreased ability to perform everyday tasks. Poor vision caused by cataracts may also result in an increased risk of falling and depression. Cataracts are most commonly due to aging but may also be caused by trauma to the eye, radiation exposure, conditions present from birth or complications from other conditions. Risk factors include diabetes, longstanding use of corticosteroid medication, obesity, other eye conditions, dietary deficiencies, smoking tobacco, prolonged exposure to sunlight and alcohol use. Cataract formation is primarily driven by oxidative stress and aging. Over time, the systems within the eye that keep the lens clear don't work as well, leading to the lens clouding. Diagnosis is typically made through an eye examination, including testing vision at various distances, slitlamp microscopy, and retinal examination. Slit-lamp examination provides further details on the characteristics, location, and extent of the cataract. An ophthalmoscope or a slit lamp with special lenses can be used to evaluate the retina. Sometimes the eye will be dilated before examination to give a better view of the retina. There are many types of cataracts, differentiated by where in the lens the clouding occurs. The three most common types of cataracts are nuclear, which affect the center of the lens, cortical which affect the outer part of the lens, and posterior subcapsular which develop at the back of the lens. As of 2025, there is no proven way to prevent or delay the...