Why does the refraction happen?

Answer 1

Refraction happens when a wave enters another medium at an angle.

The wave direction will bend towards the normal (an imaginary line perpendicular to where the two media meet) if the medium it is entering is denser and will bend away from the normal if the medium is less dense.

The density of the media directly correlates to their speed. As you probably guessed, the denser the medium the slower it is. So basically when the wave bends toward the normal because it's entering a denser medium, it does so because the medium is slower.

An example that I heard from my physics teacher and find really helpful is what I've dubbed the Lawn Mower Analogy. Basically, think of mowing a lawn (slow/dense medium) with your lawn mower (ray). So you're going at an angle and all of a sudden you hit the sidewalk (fast/shallow medium). The first wheel that hits the sidewalk starts veering faster but the other wheel's still stuck on the grass, so it starts turning towards the border (away from the normal). When both wheels are on the pavement, the angle between lawnmower now is larger than when it was on the grass.

Answer 2

Well, for one thing, the formation of an image on the retina of your eye depends on

refraction of light by the cornea, the lens, and the fluid between them. In other words,

without refraction, you might see light, but you could never see things.

Answer 3

when light enters a medium of a higher or lower density it loses or gains speed, this causes the light ray to bend.An example would be a truck moving from a road to a patch of mud.If the truck hits the mud at an angle one wheel slows down before the other and the truck swings around>

Answer 4

Our eyes use refration to bend the light through our eye lens to direct it toward the right part of the retina.

Answer 5

Eyes are built to focus an image on the retina at the back of the eyeball.

Without refraction, there's no such thing as "focus", and eyes don't work.

Answer 6

The refraction (change of direction of light) in a lens is directly related to the fact that the speed of light in glass is less than the speed of light in air.

Answer 7

Because of how light bends and reflects.