Convex lenses bend light toward a focal point and are used by farsighted patients in eyeglasses. Concave lenses spread out light and are used by nearsighted patients. Camera lenses and telescope lenses evolved from optical lenses developed for eyeglasses and help focus images. The Fresnel lens, invented in the 1800s, helped project light across seas for lighthouses. Convex and concave lenses have been instrumental in scientific discoveries since their invention in the 1300s and were a key part of Galileo's telescope inventions in the 1600s that helped launch the scientific revolution.