Nearsightedness, a more common affliction, proved more difficult to correct. It required biconcave lenses—those curving inward on each surface—that had to bring objects into focus at the ...

we design, market and manufacture high precision optical components,such as plano convex lens, plano concave lens, double convex lens, double concave lens, achromatic lens, biconvex lens, biconcave ...

It is made up of three air-spaced elements – two biconvex lenses surrounding a biconcave lens – which helps reduce distortion ...