He focused the sun's rays on a paper with a burning glass.

他用一面凸透把阳光聚焦纸上。

A physiotherapeutic apparatus for preventing and treating near sighted eye has a convex lens used as objective lens, lens cone, eyepiece, headgear and lens set.

一种防治视眼的理疗器，它有作为物的凸透、筒、目，有头套和透，它用于人们离上长时间用眼时戴眼上，可以使被视物的像清楚、放大和变远。