A cataract is a clouding of the lens in the eye which leads to a decrease in vision. Cataracts usually develop slowly and can affect one or both eyes. Symptoms may include faded colors, glare, halos around light, trouble with bright lights, and trouble seeing at night. This may result in difficulty driving, reading, or recognizing faces. Poor vision caused by cataracts may also cause an increased risk of falling and depression.
Cataracts are generally more common in older adults; however, they can occur at any age. Risk factors include diabetes, hypertension, smoking, prolonged exposure to ultraviolet light, and previous eye injury or surgery. A family history of cataracts is also a risk factor. Treatment typically involves surgery to remove the cloudy lens and replace it with an artificial one. Surgery is often successful in improving vision; however, complications such as retinal detachment or infection may occur post-operatively .
An estimated twenty million Americans aged 40 years or older have cataracts making it the most common cause of blindness globally . In 2010,. There were 6 million surgeries performed for cataract worldwide according to WHO estimates.. Of those operated on less than half regain 20/20 vision , although over 90% achieve significant visual improvement .