Refraction is the bending of light as it passes through different mediums, such as air, water, or glass.
Refraction is caused by the change in speed of light as it passes through different mediums. When light travels from a less dense medium to a more dense medium, it slows down and bends towards the normal. When light travels from a more dense medium to a less dense medium, it speeds up and bends away from the normal.
The law of refraction, also known as Snell's law, states that the ratio of the sine of the angle of incidence to the sine of the angle of refraction is equal to the ratio of the speeds of light in the two mediums.
Refraction can make objects appear distorted or shifted when viewed through different mediums. For example, objects underwater may appear closer or larger due to the bending of light as it passes through the water.
Refraction is used in many everyday objects, such as glasses and camera lenses. It is also used in optical instruments like microscopes and telescopes. Refraction is also important in the study of meteorology and the formation of rainbows.