what is refraction of light?

light travels at almos 300,000 km/s in air but slow down when it enters a diffrent materil such as water or glass.if a ray of light meets the new materail at an angle ,it bends. this bending is called refraction

as it leaves  the glass it speeds up again and so bend away from the normal. the ray emerging from this ractangular block is parallel to the ray going  in.

refrraction in different materials

when light enters amterial at an angls,it changes direction becuse its speed changes. if the material is very dense,the light slows down more and so the refraction is graeter.

apparent depth  one of the effects of refractionis that the brain can be tricked into thinking that things are in a different place from where they really are. fish can compensate for refraction between water and air. this is how they can catch insects at the surface and avoid predators such as herons.