cataracts

A cataract is a clouding of the lens inside the eye, leading to progressive visual decline. Cataracts are the leading cause of reversible blindness worldwide. Most cataracts are age-related (senile). Other causes include diabetes, eye injury, prolonged steroid use, smoking, ultraviolet exposure, and certain genetic conditions. Congenital cataracts occur at birth or in early childhood.

Types of cataracts include nuclear, cortical, and posterior subcapsular. Nuclear cataracts form in the central lens and cause gradual loss of distance vision and color changes. Cortical cataracts affect the edges of the lens with wedge-shaped opacities. Posterior subcapsular cataracts lie at the back of the lens and often impact reading and glare.

Symptoms commonly include blurred vision, glare, halos around lights, reduced contrast, and faded colors. Diagnosis is based on a comprehensive eye examination, including visual acuity testing, ophthalmoscopy, and a dilated slit-lamp examination to assess lens opacity and overall eye health.

Treatment is considered when vision interferes with daily activities. Surgical removal of the cloudy lens is performed, usually with implantation of an artificial intraocular lens (IOL). Common techniques include phacoemulsification and extracapsular extraction. Recovery is typically rapid, but complications can occur, such as infection, retinal detachment, or posterior capsule opacification, which can be treated with laser therapy.

Prevention focuses on managing risk factors where possible, such as diabetes control, smoking cessation, and sun protection. Cataracts cannot be reversed by medication or eye drops, but cataract surgery offers excellent visual rehabilitation for most patients.