Definition of cataract
1 [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
cataractousplay \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
If taken for long periods, these drops may increase the risk of cataracts and glaucoma.
Scientists aren’t sure why exercise protects against cataracts and AMD.
Research shows that people who are physically active have a lower risk of cataracts.
Normally, once cataracts are removed, lenses to improve vision are inserted.
A diet high in vitamin C – oranges, red peppers, strawberries, broccoli – may help curb cataracts by 33 percent.
Animals share many of the 30 or so most common eye ailments identified in people, Dr. Priehs said, including injuries, infections, cataracts and glaucoma, as well as some rare and inherited ones.
One of only about 400 veterinary ophthalmologists nationwide, Dr. Priehs determined that the dog had cataracts, a clouding in the eye’s natural lens that, left untreated, can eventually lead to blindness.
What a cataract of disaster has poured out upon us since then.
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.
Origin and Etymology of cataract
Latin cataracta waterfall, portcullis, from Greek kataraktēs, from katarassein to dash down, from kata- + arassein to strike, dash
First Known Use: 14th centurySee Words from the same year
CATARACT Defined for English Language Learners
Definition of cataract for English Language Learners
medical : a condition in which a part of your eye (called the lens) becomes cloudy and you cannot see well
: a large waterfall
CATARACT Defined for Kids
Definition of cataract for Students
1 : a clouding of the lens of the eye or of the cover around the lens that blocks the passage of light
2 : a large waterfall
3 : a sudden rush or flow like a waterfall
Medical Definition of cataract
: a clouding of the lens of the eye or its surrounding transparent membrane that obstructs the passage of light
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