The Eye Flashcards
What is the pupil?
the opening where light enters the eye
What is the sclera?
the white of the eye
What is the iris?
the smooth muscle, gives color to the eye
What is the optic nerve?
bundle of axons from the retina
What is the Path of Light?
cornea–> aqueous humor–> pupil–> lens–> vitreous humor–> retina
What is Myopia? What kind of lens is needed?
nearsightedness
concave lens
What is Hypermetropia? What kind of lens is needed?
farsightedness
convex lens
What is accommodation?
focusing power provided by the changing shape of the lens
When is the lens flat?
when the eye is focusing on a far point, the lens is flat
the ciliary muscles are relaxed
the zonule fibers are tight
When is the lens fat?
when the lens is focusing on a near point
the ciliary muscles are contracted
the zonule fibers are loose
What is the information flow of light?
photoreceptors–> bipolar cells–> ganglion cells
What are horizontal cells?
interneurons in the retina, they receive input from the photoreceptors and project neurites laterally to influence surrounding bipolar cells and photoreceptors
What are amacrine cells?
interneurons in the retina, they receive input from bipolar cells and project laterally to influence surrounding ganglion, bipolar, and amacrine cells
Describe RODS
- highest concentration in the periphery
- functions in low light levels best
- approx. 120 million
- 1 photopigment, rhodopsin
Describe CONES
highly concentrated in the FOVEA
function in high levels of light
approx. 6 million
3 photopigments
