SEEING THROUGH A LENS. We see the world through lenses. Eye glasses = lenses. Contact lenses = lenses. Magnifying glasses = lenses. Microscopes. - ppt download
DOUBLE CONVEX LENS, GLASS, UNMOUNTED, 50MM DIA / 100MM FL, EACH | UNI1-LCV504 | Macalaster Bicknell Company of NJ
Optic Precise Optical - Lenses are classified by the curvature of the optical surface. A simple way of explaining is convex (centre thick), concave (centre thin) and the difference is "PLUS" sign