Concave and convex curvatures of lenses bend, or refract, light in opposite ways, depending on the focal length of the lens and on the distance between the lens and the object, thus giving either a smaller or a larger image of an object. optics

Concave and convex curvatures of lenses bend, or refract, light in opposite ways, depending on the focal length of the lens and on the distance between the lens and the object, thus giving either a smaller or a larger image of an object. optics. (Photo by: Encyclopaedia Britannica/Universal Images Group via Getty Images)