Q:

How do lenses refract light?

A:

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

Full Answer

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 in Optics & Waves

Related Questions

  • Q:

    How do optical lenses work?

    A:

    Optical lenses use the principle of refraction to focus light rays or disperse them. Refraction is the bending of a ray of light when it moves between media of different densities at an angle.

    Full Answer >
    Filed Under:
  • Q:

    Why does light refract?

    A:

    Light refracts because of the differential slowing of light of different wavelengths as it passes through a medium. This means that light, which is normally made up of various wavelengths of electromagnetic radiation, reacts to a medium such as liquid or glass by slowing down. This slowing is uneven, and the rate depends on the exact wavelength of light.

    Full Answer >
    Filed Under:
  • Q:

    Can light bend?

    A:

    Yes, light can bend through diffraction and refraction. Diffraction is when light bends around a corner or a small opening and fills the larger space beyond it. Refraction is the bending of light when it transitions through different mediums, such as light seen in the air and entering into water.

    Full Answer >
    Filed Under:
  • Q:

    What is light made up of?

    A:

    Light is made of photons, which are fundamental particles. Because photons have no mass, relativistic effects allow them to travel at appropriately the speed of light.

    Full Answer >
    Filed Under:

Explore