refraction of light

refraction of light

the way in which light bends when it passes from one medium into another

Laws of refraction

1. the incident ray, normal and refracted ray are all in the same plane

2. the ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant for any two given media

the refractive index (n)

the ration of sine i to sine r when light travels from a vacuum to that medium

total internal reflection

where light is reflected back from a boundary between two media; it occurs when the light travelling towards the rarer medium from the denser one striking the boundary with an angle of incidence greater that the angle for those two media

critical angle

the angle of incidence in the denser medium which causes an angle of refraction of 90*

compound lenses

combinations of two or more lenses in contact with one another

power of a lens

the inverse of focal length

accommodation

the process of adjusting the focal length of a lens to focus distant or near objects clearly on the retina

short sightedness

distant objects cannot be seen clearly

long sightedness

near objects cannot be seen clearly