Refraction is the bending of light as it passes from one medium to another with a different density, such as from air into glass or water. This bending happens because light travels at different speeds in different materials.
Why is refraction important for lenses?
Lenses use refraction to focus or spread out light rays, which is how they form images. Here’s why it’s essential:
- Focusing Light: Convex lenses (thicker in the middle) bend incoming parallel light rays to a single point called the focal point. This principle is used in glasses, cameras, and microscopes to make clear images.
- Correcting Vision: Eyeglasses and contact lenses use refraction to correct the way light enters the eye, helping people see more clearly if their natural lens doesn’t focus light properly.
- Magnification: In magnifying glasses, microscopes, and telescopes, refraction allows lenses to enlarge images of small or distant objects.
- Image Formation: Lenses can create real or virtual images by changing the path of light. This is how projectors or even your eye’s own lens works.