Today, hundreds of lasers serve in thousands of ways. In medicine, they can destroy some cancer cells, seal detached retinas in the human eye, and perform bloodless and reconstructive surgery. In telecommunications they transmit millions of television channels and provide secure communications systems. They act as range finders or survey instruments. They can measure vast distances, and track and dock spaceships.
Lasers can guide gigantic machines that bore tunnels in hard rock.
They may check the motion of the earth crust. They can cut, drill, and weld metals. Lasers make it possible to create holograms, or three-dimensional images. Holograms on charge cards and identification cards make them less easy to forge. Holography gives clear underwater pictures and lets pilots see their instruments without looking down at them.