trifocal

a. 三焦距的 n. 三焦距透镜, 三焦距眼镜

释义与例句

adj.
  1. 1.

    Involving three foci.

    工程 物理
  2. 2.

    Of or pertaining to corrective lenses that have three different powers per eye.

    工程 物理

词源

By surface analysis, tri- + focal, or, by surface analysis, tri- + foc(us) + -al.

来源：wiktionary