Refraction By: Alicia Fadley

Refraction Refraction- the bending of a wave front as the wave front passes between two substances in which the speed of the wave differs The speed of light is different depending on what the light is traveling through. Light can travel through glass, water, ice, diamonds, and quartz. Light travels through all of these elements at different speeds. Notice that the pencil goes into the water at One point and reappears in the water at another, Making the pencil look broken. This is because the Pencil’s light is refracting in the water.

Lenses and Lenses in Nature Lenses- a transparent object that refracts light rays such that they converge or diverge to create an image The eye works as a lens also. The cornea, which is the transparent part in front of the eye, works like a lens, directing light towards the retina, in the back of the eye. There is also a small lens called the crystalline lens, that also refracts lights.

Different Lenses Convex Lenses Concave Lenses A convex lens can also Be called a converging Lens. A concave lens can also Be called a diverging lens. The focal point of the convex Lens is where the image Focuses. The focal point for a concave Lens is where the rays appear to originate.

Uses of lenses on the Eye Farsighted Farsighted or hyperopia is when the eye focuses the near image behind the retina. Distant images come in clear but near ones are blurry. To correct this, they use a convex lens. When the lens is used, the image will now focus right in front of the back of the eye. Nearsighted Nearsighted or myopia is when the eye tries to focus a far image and is focused in front of the retina. They can see images close but not far. You can fix this by uses a concave lens. This lens will help the eye to focus now farther back in the eye, right in front of the back of the eye.

Examples of Natural Refraction Sun Even when you can no longer see the sun, you can see its light. This is from the refraction, because the light bends around the earth. Mirage A mirage is when the air above the earth is so hot from being heated by the earth that it is warmer than the air at higher elevations.

Dispersion Dispersion- the index of refraction decreases with increasing wavelength. An example of this is when white light passes though a prism. Because of dispersion the colors bend at different amounts making it able to see all six colors. This fan of colors is called a visible spectrum.