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.Know More
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
A hand lens is used to magnify items. Hand lenses are used in scientific research, police work and everyday life. Hand lenses are magnifying glasses small enough to be held in a hand and easy to manipulate.Full Answer >
A converging lens is a lens curved on both sides with its center thicker than the edges. It is also commonly known as a convex lens.Full Answer >
While a regular lens is shaped like a slice from a ball, a toric lens is shaped like a slice from the side of a donut, with a hole or depression in the middle area. Toric lenses are used in contacts and glasses to correct astigmatism.Full Answer >
A condenser lens is the part of a compound microscope responsible for focusing light on the slide. This lens is included on almost all microscopes manufactured since the 19th century and is usually found on the bottom of a microscope below the stage and above the electronic light source.Full Answer >