Lenses

A lens is a curved piece of clear material, usually glass or plastic. Lenses bend light as it passes through them. This bending can make things look bigger, smaller, or sharper. Lenses are used in many tools that help us see.

Two Main Types

There are two main kinds of lenses. A convex lens is thicker in the middle and thinner at the edges. It makes things look bigger, like a magnifying glass. A concave lens is thinner in the middle and thicker at the edges. It makes things look smaller and is used in some eyeglasses.

Lenses Everywhere

Lenses are used in many important tools. Eyeglasses help people see better by bending light just right. Cameras use lenses to take sharp pictures. Telescopes use lenses to see stars and planets far away. Microscopes use lenses to look at tiny things like germs. Even your own eyes have natural lenses inside them.

Fun Facts

• The first eyeglasses were made in Italy about 700 years ago.
• A magnifying glass can focus sunlight enough to burn paper.
• The Hubble Space Telescope uses giant mirrors and lenses to see galaxies far away.

Did You Know?

Your eye has a lens inside it that changes shape to help you focus on things that are near or far.