convex lens

1.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.

一种防治近视眼的理疗器，它有作为物的凸透、、，还有头套和透，它用于人们在近距时间用眼时戴在眼，可以使被视物的像清楚、放大和变远。