How Does Refraction of light | Physics | Khan Academy Work?

Light changes direction when it moves from one material to another, that’s refraction.

Imagine you're running on a playground, and suddenly you step onto a wet patch of grass. You slow down, and your path bends slightly. That's kind of like what happens with light.

When light goes from air into water, it slows down, just like you slowing down on the wet grass. Because it slows down, its direction changes too. This is why a straw in a glass of water looks bent, it’s not really bent, but the refraction makes it look that way.

You can see this every day when you look at a fish in a pond. The light from the fish bends as it leaves the water and enters your eyes, making the fish appear closer to the surface than it actually is.

It’s like seeing a friend through a window, their face looks a little squished or shifted because of how refraction works! Light changes direction when it moves from one material to another, that’s refraction.

Imagine you're running on a playground, and suddenly you step onto a wet patch of grass. You slow down, and your path bends slightly. That's kind of like what happens with light.

When light goes from air into water, it slows down, just like you slowing down on the wet grass. Because it slows down, its direction changes too. This is why a straw in a glass of water looks bent, it’s not really bent, but the refraction makes it look that way.