| 释义 |
tri·focal
I. \“+\ adjective
Etymology: tri- + focal
1. : having three focal lengths
2. of an eyeglass lens : having one part that corrects for near vision, one for intermediate vision (as at arm's length), and one for distant vision
II. noun
(-s)
1. : a trifocal glass or lens
2. trifocals plural : eyeglasses with trifocal lenses — compare bifocal 2 |