cataract

American  

[kat-uh-rakt] / ˈkæt əˌrækt /

noun

1. a descent of water over a steep surface; a waterfall, especially one of considerable size.

2. any furious rush or downpour of water; deluge.

3. Ophthalmology.

   1. an abnormality of the eye, characterized by opacity of the lens.

   2. the opaque area.

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cataract British  

/ ˈkætəˌrækt /

noun

1. a large waterfall or rapids

2. a deluge; downpour

3. pathol

   1. partial or total opacity of the crystalline lens of the eye

   2. the opaque area

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cataract Scientific  

/ kăt′ə-răkt′ /

1. An opacity of the lens of the eye or the membrane that covers it, causing impairment of vision or blindness.

2. A waterfall in which a large volume of water flows over a steep precipice.

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cataract Cultural  

1. A loss in the transparency of the lens of the eye, which reduces a person's ability to see. The condition can be treated by surgically removing the lens and replacing it with an artificial one, or with corrective eyeglasses or contact lenses.

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Other Word Forms

• cataractal adjective
• cataracted adjective
• cataractous adjective

Etymology

Origin of cataract

First recorded in 1350–1400; Middle English cataracte, from Latin catar(r)acta, from Greek katarráktēs “waterfall, floodgate, portcullis” (noun), “downrushing” (adjective), from katarássein “to dash down,” from kat- cata- + arássein “to dash, smite”

Explanation

If someone has a cataract in their right eye, their lens is cloudy rather than clear, so they have difficulty seeing. Luckily, cataracts are easily removed. Cataracts, cloudy areas of the lenses of the eye, are often associated with old age. Cataract can also mean a large waterfall, like Niagara Falls. Even with cataracts, you can still make out a cataract. It's not a little waterfall; it's huge!

Example Sentences

He said doctors told him he’ll require surgery to remove the cataract before they can determine that.

From Los Angeles Times • Jan. 16, 2026

Back in 1978, a surgeon had bungled cataract surgery, leaving him blind in his left eye.

From The Wall Street Journal • Nov. 27, 2025

And Medicare only pays the bottom level of cataract replacement lens—so people typically want to pay out of pocket to get the upgraded version.

From Barron's • Nov. 25, 2025

I have taken one vacation in 17 years, to get cataract surgery.

From MarketWatch • Oct. 9, 2025

The two floods combined in a steaming, boiling cataract and flowed on as one toward the black fog.

From "The House of Hades" by Rick Riordan