How Lenses Bend Light

Depending on the shape of the lens, it will have varying effects on light as it passes through.

Lenses bend light through a method referred to as refraction. Depending on the shape of the lens---whether it is concave, convex or a prism---it will have a different effect on light as it passes through.

Convex

The glass of a convex lens is shaped outward. If you imagine a bowl, a convex lens would look like the bottom of the outside of the bowl. When light hits a convex lens it is refracted inward, making the light beams meet at a focal point.

Concave

A concave lens has glass that bends in. Using the bowl example, it would be like the inside of the bowl. When light hits a concave lens it is refracted in an outward direction.

Prism

A prism is two planar, or flat, lenses that are positioned at an angle; it creates a rainbow when light passes through. It does this by breaking apart the visible light into its basic colors of red, orange, yellow, green, blue, indigo and violet.

References

• Explain That Stuff: Lenses
• Physics4kids.com: Bending Light with Refraction