1. How do I see color? Photochemical receptors receive the light (____ and _____) Rods-brightness cones-the color They release a ________ signal to the brain. Brain interprets the signal Primary colors of light: red, blue, green (mix together to make white.)

2. Optics and Reflection Optics-the study of how light behaves Deals with the collection and use of light to create images Includes: lenses, mirrors, and ______ Law of __________: determines the reflected ray Light rays bounce off a mirror at the same angle at which they arrive We always define angles relative to the normal (the line perpendicular to the mirror (or lens)

3. Mirrors & Prisms Mirrors reflect light – Flat mirrors show _______ – Curved mirrors cause light to come together or spread apart Prisms cause light to change directions – Traditionally used to ________ the colors of light and to show how light bends

4. Reflection & Mirrors A mirror reflects rays of light so that they change their path ___________– the ray that comes from the object and hits the mirror ___________– the ray that bounces off the mirror

5. Refraction and Lenses A ____ uses __________ to cause light to come together or spread apart Refraction – The bending of light that occurs when light crosses a boundary between two different substances – EX. Glass, Plastic, Water ____ – a shape of transparent material that is used to bend the light rays – Shape determines how much the light bends

6. Focal Point & Focal Length ___________– the point at which light rays meet after having entered a converging lens parallel to the principal axis. ____________- the distance from the center of the lens to the focal point Where is the focal point in this eye diagram? Where is the focal length?

7. Lens Types Converging lenses – bend parallel light rays passing through them inward ______ the focal point Diverging lenses – bend the parallel light rays passing through them outward ______ from the focal point

8. The Eye Lens, cornea, iris, retina optic nerve Two convex lenses, refraction

9. Lens The lens can change it’s shape to focus at different distances. A lens that focuses in front of the retina is a condition called myopia (near sightedness) A lens that focuses objects behind the retina is a condition called hyperopia (far sightedness) Long Focal Length Short Focal Length Use Diverging Lens Thicker on sides than in center Use Converging Lens Thick in center than on the sides