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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.


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

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

cataract Scientific  
/ kătə-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.


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.


Other Word Forms

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!

Keep Reading on Vocabulary.com

Vocabulary lists containing cataract

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Piush Khetan, the charity's India director, said they offer basic services which include a free eye screening and glasses for people in need as well as performing cataract surgery.

From Barron's • May 27, 2026

The Welsh government said the extra 187,000 outpatient appointments that health boards had delivered, and 37,000 cataract operations to date, were because of the additional funding this year.

From BBC • Mar. 19, 2026

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

He had studied it after his botched cataract surgery but never mastered it.

From The Wall Street Journal • Nov. 27, 2025

“They’ll take her if we do a cataract operation on her right eye. On a hippopotamus! What next? Nose jobs on the rhinos?”

From "Life of Pi" by Yann Martel

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