Chapter 16 4 Refraction Lenses and Prisms PEPS

Chapter 16. 4: Refraction, Lenses, and Prisms PEPS Mr. Taylor Rainier Jr/Sr High School

Refraction of Light • Refraction is when waves bend when passing from one medium to another. – This is because the wave travels at different speeds in the 2 media.

Refraction of Light • If the speed of the wave is faster in the new medium, the wave will bend away from the normal. • If the speed of the wave is slower in the new medium, the wave will bend toward the normal.

Lenses • Lenses use light refraction to change the direction of light. – Convex lenses bend light inward. • Are called converging lenses. – Concave lenses bend light outward • Are called diverging lenses.

Lenses • Converging lenses can magnify objects. – Magnifying lenses have a focal point where all the light rays converge on a single point. – Microscopes and binoculars use converging lenses to magnify the objects.

Eyes • The eye has a lens that focuses light on your retina – The retina has rods (for black & white vision) and cones (for color vision). – The cornea also refracts light and is responsible for 70% of the focus of the eye.

Prisms • Prisms can separate light into different bands because of the different speeds of light through the medium. This separation is called dispersion. • Rainbows are the result of dispersion of light through raindrops. • Sunsets are the result of dispersion of sunlight through the atmosphere.