TEST 4-Vision Flashcards
Conjunctiva
thin skin layer, transparent
conjunctivitis: pink eye, can be bacterial or virus or particles in the eye (contagious if bacterial or virus)
Cornea and Sclera
part of the whole outer part of the eye, holds everything in place, keeps stuff in
Cornea-transparent, astigmitism: light does not pass through evenly, imperfection of cornea or lens
Sclera- white with blood vessels
Aqueous Humor
watery liquid in chamber behind cornea
we continually produce
provides nutrients and oxygen to cornea
maintains pressure in the eye
too much pressure-will damage the veins and arteries on the back of the eye-stopping blood flow
too much liquid-glaucoma-become blind if not treated
Canal of Schlemm
drains all excess aqueous humor
Pupil
opening
dark-bigger, light-smaller
hole, no color
Iris
muscle, controls pupil size
color
Lens
focuses the image
changes the shape, moves
bends light to focus
add layers of lens-like a tree-lose amount of adjustment of muscles (reading glasses)
too much sun-cloudiness blocks light
cataracts-layers on lens aren’t transparent
Vitrious Humor
jelly-like substance that supports the eye space
filler, we can’t make more
Retina
attached in one place (optic nerve), otherwise completely free
light receptors
types of receptors: rods (detect light intensity) [black and white]
cones (detect color, require lots of light to activate)
Fovea
highest density of receptors (majority cones)
Blind Spot
retina meets optic nerve
Color Blindness
color vision
affects cones
males more likely
red-green or blue-yellow
Optic Nerve
goes to the brain
20/20 vision
the bottom number is how far away someone with 20/20 vision can see
Binocular Vision
2/eye
depth perception
