| Question | Answer |
| Name the primary organs of vision | Eye
optic nerve
Chasm &tract cranial N. 2
thalamus of the brain
Primary visual cortex
Lateral geniculate nucleus, in the thalamus |
| Eye is long | myopia |
| Lens is clouding up | cataracts |
| Loss of lens elasticity | presbyopia |
| Poor drainage of aqueous humor by canal of schlemm | glaucoma |
| Eye is short | hyperopia |
| Irregular curvature of the lens or cornea | astigmatism |
| Symptom of myopia? | Objects appear blurry far away
Difficulty seeing close objects |
| symptom of cataracts? | Lens is clouding up |
| symptom of presbyopia? | Loss of lens elasticity |
| symptom of glaucoma? | Poor drainage of aqueous humor by canal of schlemm |
| symptom of hyperopia? | Eye is long,farsighted objects are blurry close up |
| symptom of astigmatism? | Irregular curvature of the lens or cornea |
| Secondary organs of vision | Extra-ocular eye muscles
Eyelids
conjunctiva,
lacrimal apperatus |
| Function of the retina | thin layer of tissue lines the back of the inside of the eye , it receives light that the lens has focused converts into neural signals and then sends these signals to the brain for visual recognition. |
| optic nerve function | Transfers visual information from the retina to vision centers of the brain, via electrical impulses. |
| optic nerve made up of? | ganglionic cells or nerve cells of over one million nerve fibers |
| Rods- type 1 of 2 types of photo receptors | *Night vision- light sensitive
*can fire in low light only once
* Best for peripheral vision
* peripheral has majority of rods.
* Only one type of rod.
+not at the back of eye
Front and side only |
| Cones- 2nd type of photo receptors | Day vision or color vision
Less sensitive to light
Best for central vision+very little at sides
3 types of cones:
red
blue
green cones |
| What is the visual reflex center called? | Superior colliculus |
| Where is there an increase in intra-ocular pressure? what is the pathology? describe | glaucoma |
| Where is the primary structure of vision located? | The visual reflex center -superior colliculi |
| accommodation reflex | |
| Where is the greater amount of cones located? | The macula lutea |
