trifocal en · ADJ
Etymology
By surface analysis, tri- + focal, or, by surface analysis, tri- + foc(us) + -al.
Meanings
- (not-comparable) Involving three foci.
- (not-comparable) Of or pertaining to corrective lenses that have three different powers per eye.
Coordinates
confocal · bifocal · quadrifocal · confocal · bifocal · unifocal · unifocal