trifocals

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English[edit]

Etymology[edit]

English Wikipedia has an article on:
Wikipedia

From tri- + focal (see focus). Coined by John Isaac Hawkins, their inventor, in 1826.

Noun[edit]

trifocals pl (plural only)

  1. (optics) Spectacles with corrective lenses that have three different powers per eye.

Related terms[edit]

Translations[edit]