| A | B |
| regular reflection | Reflection off a smooth surface. |
| refraction | Change in direction (bending) of light at a boundary between two media. |
| diffuse reflection | Reflection off a rough surface. |
| Law of Refraction | Snell's Law which states a ray of light bends in such a way that the ratio of sine of the angle of incidence to the sine of the angle of refraction is constant. |
| Law of Reflection | Angle of incidence = angle of reflection. |
| critical angle | Angle at which total internal reflection occurs. |
| total internal reflection | Condition when no refraction occurs. |
| index of refraction | Measure of the amount that light bends when passing into a medium from a vacuum. |
| Total internal reflection CAN occur | when light passes from a more dense to a less dense medium. |
| Total internal reflection CANNOT occur | when light passes from a less dense to a more dense medium. |
| rainbow | Refraction occurs from light going into and out of a rain droplet. Total internal reflection occurs at the back of the drop. |
| mirage | Light refracts to the eye off of the warmer air near the earth. Light appears reflected. |
| speed of light | 3 EE8 m/s in a vacuum. |
| index of refraction of light in a vacuum | 1 |
| index of refraction of light in air | approximately 1 |