Hand held optical lens

Concave and convex lenses are fundamental optical devices with distinct properties. A concave lens is thinner at the center and thicker at the edges, causing light rays passing through it to diverge. It is used to correct nearsightedness and in certain imaging systems. Conversely, a convex lens is thicker at the center and thinner at the edges, causing light rays passing through it to converge. It is employed in correcting farsightedness and in magnifying objects, such as in cameras and telescopes.

凹透鏡和凸透鏡是具有不同特性的基本光學元件。 凹透鏡中心較薄，邊緣較厚，導致穿過凹透鏡的光線發散。 它用於矯正近視和某些成像系統。 相反，凸透鏡中心較厚，邊緣較薄，導致穿過它的光線會聚。 它用於矯正遠視和放大物體，例如相機和望遠鏡。