LASER is an acronym for “Light Amplification by Stimulated Emission of Radiation.” In this definition radiation doesn’t refer to nuclear radiation, but to electromagnetic radiation. The electromagnetic spectrum includes radio waves, microwaves, infrared light, visible light, ultraviolet radiation, and X-rays. Some light wavelengths are visible, and other are not unless special equipment is used (e.g., infrared cameras, night-vision goggles). How is a beam of light able to delicately reshape the surface of the eye, yet still be able to cut steel in a laser cutting machines?Lasers operate by concentrating the strength of various forms of light. The strengthened beam is an almost perfectly straight beam, called a coherent beam. “Coherent” means that almost all of the light energy (photons) are traveling in the same direction. The laser light energy stays focused on a smaller area with greater power. A closer analogy to a laser is a magnifying glass. Remember as a child how you got the sun’s rays to focus on a tiny spot that got hot enough to burn? That’s similar to what a laser does, unless you moved the magnifying glass. Then the focus was lost and the sunlight was no longer concentrated. Because the laser employs a coherent beam, that essentially means it stays focused no matter the distance! Think of it link an infinite magnifying glass.

Lasers can perform a multitude of different tasks at different power levels. Specific light wavelengths and beam strengths can be achieved by altering the light source, power source, and even the color of the light. This extreme versatility allows both the shaping of a delicate cornea and the cutting of industrial steel. Laser has been proven to be beneficial for us, that’s why scientists keep doing researches on this technology.