physics - the human eye Flashcards
controls amount of incoming light
iris - diaphragm
allow light to enter
pupil - apeture
refracts light and forms sharp image
cornea - converging lens
creates image on a screen
retina - light-sensitive film or digital senser
eye lens and cornea combination produces an __,__,__ image on the brain where it translates to an upright image
smaller, real, inverted
hyperopia (far sightedness)
-trouble seeing close
-occurs because the distance between lens and retina is too small and lens/cornea is too weak
-positive meniscus lens
presbyopia (age)
-eye loses elasticity
-glasses with converging lens
myopia (near-sightedness)
-cant focus on far objects
-distance between lens and retina is too large or cornea/lens combination is too strong
-negative meniscus
astigmatism
caused by too much fluid behind cornea+ blur along 1 direction
glaucoma
fluid build up, increasing pressure and changing shape, dark and light spots
cataracts
proteins on surface of lens causes light to disperse and create a blurry vision
examples of lens applications
-camera
-film projector
-magnifying glass
flattened sun
denser air near surface - refraction
apparent sunsets
temperature differences - light bends
water on pavement - mirage
-temperature affects density of air - hot close to the road is hotter, causing light to bend