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

---

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.

---

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

• 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

The targets were backed up by £120m of extra funding which he said would be targeted at providing more outpatient appointments, diagnostic tests and treatments, including more than 20,000 cataract operations.

From BBC • Apr. 22, 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 has spearheaded efforts to plant trees, clean up oceans, rivers and beaches, pay for strangers’ cataract surgeries and prosthetic limbs and has donated millions to charities such as Make-A-Wish and food banks.

From The Wall Street Journal • Jan. 3, 2026

And at some point, most people will need cataract surgery.

From Barron's • Nov. 25, 2025

The cataract of Saint-Jean-les-Eaux plunged between pinnacles of rock at the eastern end of a spur of the Alps, and the generating station clung to the side of the mountain above it.

From "The Amber Spyglass" by Philip Pullman