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

Derived Forms

• cataractal
  adjective
• cataractous
  adjective
• cataracted
  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

And the fabled eye of CBS may grow a cataract at the prospect of being jeered from the stage of the nearly 6,000-seat Radio City Music Hall, to what would be resounding applause.

From The Wall Street Journal • Jun. 4, 2026

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

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

As a side effect of his surgery, Hamid said he later developed a cataract in his right eye and chose to have it treated privately before it affected his vision.

From BBC • Jan. 12, 2026

A dozen pigeons roosting on the cathedral spire cataract down its length and wheel out over the sea.

From "All the Light We Cannot See" by Anthony Doerr