A lens refracts light by slowing it down and bending it with regard to the "normal" line, a line at a right angle to the surface of the lens. When the light passes through the far side of the lens and speeds up, it bends away from "normal," refracting further.Continue Reading
When the focal point is behind a lens, as when a person is looking at an object, the light moves toward that person's eyeglasses or contact lenses in parallel lines. When the light rays hit the lens, they are no longer traveling through the air; instead, they are traveling through a solid, generally glass or plastic. The increased density of this new substance slows the light down; even though the change of speed is infinitesimal, it is enough to alter the path of the ray of light.
The new path for the light ray adjusts to the "normal" line -- a line perpendicular to the surface of the lens. The light ray does not turn to follow the line but instead takes an angle between its original one and that perpendicular line. On the other side of the lens, moving out of the lens causes another change in speed, because the density of its environment has lessened once again. The light ray takes another turn, heading to meet other formerly parallel light rays at the focal point.Learn more about Optics & Waves
The exact composition of light has eluded physicists for years, but the predominant theory is that light is comprised of a kind of energy called electromagnetic radiation. This energy behaves like a wave and a particle in different situations. Scientists believe electromagnetic radiation is composed of bundles of energy called photons.Full Answer >
The human eye sees light with the pupil and the retina. Located inside the retina are two types of special cells called photoreceptor cells. There are two varieties of photoreceptor cells known as cones and rods.Full Answer >
The bending of light, sound or heat waves is known as refraction. Refraction occurs when a light wave, heat wave or sound wave moves from one medium to another.Full Answer >
Even though light has been visible to humans for thousands of years, it was Sir Isaac Newton who managed to understand what light consists of. Newton was the first person to realize that white light consists of a mix of light rays of various colors.Full Answer >