1. Refraction

2. Refraction of Light When light waves pass from one medium to the next, its speed changes, causing it to bend. Going from lower to higher index of refraction, slows and bends toward normal Going from higher to lower index of refraction, it speeds up and bends away from normal. The bending of light through glasses or contact lenses causes images to come into focus for people with vision problems.

3. Refraction of Light

5. Lenses Transmits and refracts light through its translucent curved surface to form an image. Used in a variety of optical instruments: cameras, telescopes, microscopes, magnifying glasses, eye glasses. Two common types: concave and convex

6. Concave Lens Thinner in middle and thicker at edge Causes parallel rays to diverge Images produced are reduced, upright, and virtual

7. Concave Lens

8. Convex Lens Thicker in the middle and thinner at edge Properties of image depend on distance of object from lens Object beyond focal point, a real and inverted image is formed Object at the focal point, refracted light rays are parallel Object is between lens and focal point, an upright and virtual image will form

9. Convex Lens