Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
37 Cards in this Set
- Front
- Back
|
clilary muscles |
change shape of lense and move lense |
|
|
lense thickens when |
looking at close objects. cillary muscles contract to thicken lense |
|
|
lense thins when |
focusing distance. cillary muscles relax |
|
|
fovea |
most focused point |
|
|
the farther the object |
the more parrellel the lines |
|
|
the closer the object |
the light is at an angle |
|
|
pupil dim light |
hole in irisi. dim light stimuates radial and pupil dilates |
|
|
pupil bright liht |
bright light stimulates circular muscles and constricts |
|
|
aqueous humor |
fluid in anterior cavity of eye. secreted by epithelium on inner surface of the cillary body. Provides nutrients. |
|
|
canal of schelemm |
fluid (aqueous humor) leaves anterior cavity of eye through this. |
|
|
glaucoma |
build of of aqueous humor fluid. too much pressure and damage to optic nerve. blood vessels that serve retina compressed. |
|
|
lens |
10 mm, continues to grow through out life. capsule, epithelium, lens fibers. Long, thin, transparent cells. blocks most UV light. No vessels or nerves. |
|
|
presbyopia |
age related loss of accommodation, near point further. lens becomes less flexible. |
|
|
eye color |
polygenic trait (15 genes) also blue eyes dont have any PIGMENT. just crytalized and reflects light back at you (like the sky) |
|
|
stroma |
front layer of iris. |
|
|
why do babies eyes change color? |
melonocytes in iris develop as they age. |
|
|
inner tunic or retina |
outgrowth of developing brain as a "cup" Contains visual receptors. continous with optic nerve. ends just behind margin of ciliary body. composed of several layers. |
|
|
marcula lutea |
yellow spot in retina |
|
|
fovea centralis |
center of macula lutea, produces sharpest vision. "packed with cones" |
|
|
optic disc |
blind spot, contains no visual recepors |
|
|
vitreous humor |
clear, lets light through and keeps eye from collapsing |
|
|
floaters |
can get this in the vitrous humor. |
|
|
macula |
dark orange spot directly back from optic disc. no blood vessels go to this cuz they would obscure light |
|
|
posterior cavity |
contains vitreos humor. |
|
|
layers of eye (WILL BE ON TEST) |
fibrous tunic, vascular tunic, and retina. |
|
|
Light goes throuogh all of _____ before we see it |
nerves. this is also why we have a blind spot because they have to leave somewhere |
|
|
horizontal and amacrine cells |
modify impulses |
|
|
receptor cells, bipolar cells, ganglion cells |
provide pathway for impulses triggered by photoreceptors to reach optic nerve. |
|
|
nerve cells right before optic |
ganglion cells |
|
|
light refraction |
bending of light. occurs when light waves pass at oblique angle into mediums of diff densities. |
|
|
convex lens |
cause light waves to converge |
|
|
myopia |
short sighted |
|
|
hyperopia |
far sighted |
|
|
astigmatism |
defect in curvature of cornea or lens. some portions blurred, ciliary muscles fatigue trying to accomodate |
|
|
two types of photoreceptors |
rods and cones |
|
|
rods |
you have more of these. 120 million. more light sensitive but don't distinguish colors |
|
|
cones |
6 million. distinguish colors but are not as light sensitive. |
