The Staoptics Biconvex Hand-held Magnifiers include lightweight PMMA lenses that feature edge-to-edge sharpness and have an anti-static coating. The magniying glass is composed of transparent PMMA which provides maximum light and shadow-free viewing. The magnifiers also have an additional 10x pano-convex lens integrated into the handle for viewing even smaller details and The handle has 2x magnification and can be read line by line. Biconvex lenses are manufactured with an identical convex surface on both sides of the lens-in other words,there is one concave lens on both faces. Bi-convex lenses have positive focal lengths and form both real and virtual images. If the lens is biconvex or plano-convex, a collimated beam of light travelling parallel to the lens axis and passing through the lens will be converged to a spot on the axis,at a certain distance behind the lens,known as the focal length. Staoptics 3in1 magnifying glass is a perfect gift for children and the elderly.It is very suitable for people who read books, view maps, jigsaw puzzles,magazines,newspapers,electronic products,medical instructions,and check small fonts and low-vision macular degeneration.