A cataract is a clouding that forms in the lens of an eye, making it harder to see clearly. Think of looking through a foggy window: everything becomes blurry, colors seem duller, and bright lights might create uncomfortable glare. That's what vision feels like with a cataract.

As people age, the proteins in their eye lenses can clump together and create these cloudy patches. It's like how clear egg whites turn cloudy and white when you cook them. Most cataracts develop slowly over years, gradually making reading or recognizing faces more difficult. Fortunately, doctors can remove cataracts through surgery and replace the clouded lens with a clear artificial one, restoring vision.

The word also describes a large, powerful waterfall where water crashes down with tremendous force. Niagara Falls is sometimes called a cataract.