cataract

noun cat·a·ract \ ˈka-tə-ˌrakt \

|Updated on: 21 Jun 2018

Definition of cataract

[Middle English, from Medieval French or Medieval Latin; Medieval French catharacte, from Medieval Latin cataracta, from Latin, portcullis]

: a clouding of the lens of the eye or of its surrounding transparent membrane that obstructs the passage of light

2 a obsolete : waterspout

b : waterfall; especially : a large one over a precipice

c : steep rapids in a river

the cataracts of the Nile

d : downpour, flood

cataracts of rain

cataracts of information

—

cataractous

play \ˌka-tə-ˈrak-təs\ adjective

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Examples of cataract in a Sentence

the roaring cataract is one of the park's most majestic sights
in spring the melting snows usually produce a cataract that inundates the valley

Recent Examples of cataract from the Web

Ultraviolet rays may play a role in the development of cataracts as well as growths on the surface of the eye called pterygiums, which can impede your vision.

— amanda gardner, Health.com, "Why Those Tiny Sunglasses Celebs Love Aren't Actually Good for Your Eyes," 13 June 2018
In the years after the attack, some survivors would endure amputation, paralysis, severe scarring, twisted torsos and limbs, cataracts, thyroid disease, and heart disease.

— Daily Intelligencer, "This Is What a Nuclear Bomb Looks Like," 12 June 2018
Rumor also underwent surgery to remove his left eye which was damaged due to trauma caused by an ulcer and to repair his right eye, which had a cataract.

— Fox News, "Abandoned dog with one eye undergoes incredible transformation," 26 Apr. 2018
Other risk factors for cataracts include smoking and diabetes.

— jill u. adams, courant.com, "For Your Eyes: Sunglasses Even On A Cloudy Day," 31 May 2018
Also, the sun can put a person at risk for cataracts.

— lauren castle, azcentral, "Eye protection is just as important as sunscreen in the Arizona summer," 17 May 2018
The team will sedate the dogs and look for tumors and cataracts, which can signal radiation poisoning.

— jason daley, Smithsonian, "Chernobyl Puppies Going Up for Adoption in the U.S.," 16 May 2018
His left eye had to be removed and his right eye had a cataract.

— william axford, Houston Chronicle, "'Rumor' just one of many dogs abandoned in Houston's 'Corridor of Cruelty'," 26 Apr. 2018
People with uncontrolled or poorly controlled diabetes are also at a higher risk for eye issues like cataracts, which can occur when the lenses of your eyes cloud up, says Dr. Lorenz.

— korin miller, SELF, "6 Weird Reasons Your Vision Is Blurry," 4 May 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'cataract.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Did You Know?

The meaning of "cataract" we're most familiar with is also the oldest. It dates to the 14th century and comes from the Latin word cataracta, meaning "portcullis," probably because the ocular cataract obstructs vision in a way reminiscent of the way the portcullis's heavy iron grating obstructs passage into a fortress or castle. Latin cataracta has another meaning, however-"waterfall"-and that meaning gave us the water-related meanings that came in later centuries. The connection between the two Latin meanings can be seen in katarassein, the Greek source of cataracta. It means "to dash down"-an action we see in both the slamming portcullis and the cascading waterfall.