| A | B |
|---|
| opaque | a material that reflects or absorbs all light that strikes it |
| transparent | a material that transmits light |
| translucent | a material that scatters light as it passes through |
| ray | straight line used to represent a light wave |
| regular reflection | reflection that occurs when parrallel rays of light hit a smooth surface and all reflect at the same angle |
| diffuse reflection | reflection that occurs when parrallel rays of light hit a rough surface and all reflect at different angles |
| image | a copy of an object formed by reflected or refracted rays of light |
| plane mirror | a flat mirror that produces an upright, virtual image the same size as the object |
| virtual image | an upright image formed where rays of light appear to meet or come from |
| concave mirror | a mirror with a surface that curves inward |
| focal point | the point at which rays of light meet, or appear to meet, after being reflected (or refracted) by a mirror (or lens) |
| real image | an inverted image formed where rays of light meet |
| convex mirror | a mirror with a surface that curves outward |
| index of refraction | the measure of how much aray of light bends when it enters a new medium |
| mirage | an image of a distant object caused by refraction of light as it travels through air of varying temperature |
| concave lens | a lens that is thinner in the center than at the edges |
| convex lens | a lens that is thicker in the center than at the edges |
| primary color | 3 colors that can be used to make any other color |
| secondary color | any color produced by combining equal amounts of any 2 primary colors |
| complimentary colors | any 2 colors that combine to form white or black pigment |
| pigment | a colored chemical compound that absorbs light; pigments are opaque and are used to color other materials |
| cornea | the clear tissue that covers the front of the eye |
| retina | the layer of receptive cells at the back of the eye on which an image is focused; nerve impulses are sent from the retina to the brain |
| pupil | the opening through which light enters the eye |
| iris | the ring of colored muscle that surrounds the pupil and regulates the amount of light entering the eye |
| rods | cells on the retina that detect dim light |
| cone | a cell on the retina that detects color |
| optic nerve | short, thick nerve that carries signals from the eye to the brain |
| farsighted | the condition in which distant objects can be seen clearly but nearby objects look blurry |
| nearsighted | the condition in which nearby objects can be seen clearly but distant objects look blurry |
| telescope | an optical instrument that forms enlarged images of distant objects |
| refracting telescope | a telescope that uses convex lenses to gather and focus light |
| objective lens | lens that gathers light from an object and forms a real image |
| eyepiece lens | a lens that magnifies the image formed by the objective lens |
| reflecting telescope | a telescope that uses one or more mirrors to gather light from distant objects |
| microscope | an optical instrument that forms enlarged images of tiny objects |
| camera | optical instrument that uses lenses to focus light and record an image of an object |
| laser | a devise that produces coherent light |
| hologram | a 3 dimensional photograph formed by the interference between 2 laser beams |
| optical fiber | a long,thin strand of glass or plastic that can carry light for long distances without allowing the light to fade out;can be used for transmitting messages |
| total internal reflection | complete reflection light by the inside surface of a medium |
