Science
How does refraction work?
Refraction is the bending of light as it passes from one material into another, like from air into water. Light changes speed when it enters a new medium, and that speed change makes it bend — which is why a straw looks broken in a glass of water.
See it in motion.
Watch a 2-minute animated lesson that shows exactly how refraction works.
Step by step
- 1Light bends when it passes between materials.
- 2It happens because light changes speed in each medium.
- 3It's why lenses focus light and straws look bent.
- 4Different colors bend by different amounts, making rainbows.
Frequently asked questions
- How does refraction work?
- Light changes speed entering a new material, and that speed change bends its path.
- Why does a straw look bent in water?
- Light from the underwater part refracts as it leaves the water, shifting where the straw appears.
- How do lenses use refraction?
- Their curved shape refracts light to focus it, as in glasses, cameras, and telescopes.