What is a cataract?

What is a cataract?

• A. A tear in the retina
• B. An inflammation of the iris
• C. An opacity of the lens
• D. Increased intraocular pressure

Answer: (C)

A cataract is an opacity of the lens. The lens in the eye must be clear to let light pass through and focus on the retina. With a cataract, proteins in the lens clump or denature over time, causing cloudiness. This clouding scatters light, leading to blurred vision, glare, and reduced contrast, especially in bright light or at night. Cataracts are a lens problem, not an issue with the retina, iris, or the pressure inside the eye. For comparison, a tear in the retina affects the retina itself, inflammation of the iris is an anterior uveitis, and increased intraocular pressure relates to glaucoma. When cataracts interfere with daily vision, the typical treatment is surgical removal of the cloudy lens with replacement by a clear artificial lens.

A cataract is an opacity of the lens. The lens in the eye must be clear to let light pass through and focus on the retina. With a cataract, proteins in the lens clump or denature over time, causing cloudiness. This clouding scatters light, leading to blurred vision, glare, and reduced contrast, especially in bright light or at night. Cataracts are a lens problem, not an issue with the retina, iris, or the pressure inside the eye. For comparison, a tear in the retina affects the retina itself, inflammation of the iris is an anterior uveitis, and increased intraocular pressure relates to glaucoma. When cataracts interfere with daily vision, the typical treatment is surgical removal of the cloudy lens with replacement by a clear artificial lens.