vision Flashcards
blind spot test
the retina is incomplete where the optic nerve leaves the eye which cause a blind spot
color blindness test
three or more incorrect responses indicates that your partner may have deficient color vision
snellen visual activity test
20/20 vision test.
located superior to the eye, they partially shade the eyes and protect them from sweat.
eyebrows
located over the eye.
the eyelids blink to moisten the eye and sweep foreign substances from the eyes surface
eyelids
located on the margin of the eyelids.
prevent foreign substances from entering the eye
eyelashes
composed of lacrimal(or tear) gland and lacrimal ducts.
secretions or tears from the gland moisten the eye and washes away foreign substances
lacrimal apparatus
an epithelial covering on the inside of the eyelid and the anterior surface of the eye.
helps keep the cornea moist and clean
conjuctiva
the superior oblique rotates the inside of the eye downward and medially.
the inferior oblique rotates the eye upward and medially
oblique eye muscles
the four muscles are the superior, inferior, medial, and lateral rectus muscles.
these muscles move the eye up, down, medially and laterally.
rectus eye muscles
these are jelly-like fluids that fill the interior walls of the eye
aqueous and vitreous humours
commonly called the WHITE OF THE EYE. a tough, tendon-like layer continuous with the dura mater of the brain around the optic nerve. it shapes the eye and is the insertion point for the six muscles which control eye movement
Sclera
the most anterior layer of the eye that is continuous with the sclera.
transparent to allow light into the eye. well supplied with nerve endings for pain, reflex, blinking, and to stimulate lacrimal secretions.
it also lacks blood vessels
cornea
separates the fibrous and sensory tunics
contains a dense capillary bed that provides oxygen and nourishment to the eye.
also contains many melanocytes
choroid
lies just beneath the cornea.
this layer to which we attribute eye color.
composed of two layers of pupilary muscles that control the diameter of the pupil, and thus the amount of light entering the eye
iris
this is the round central opening in the center of the eye
pupil
a thick ring of tissue attached to and lies beneath the iris
ciliary body
located beneath the iris and held in the center of the pupil by suspending ligaments extending from the ciliary body
lens
the delicate, two innermost layer of the eye.
contains photoreceptors and neurons that react to light and transmit and integrate visual signals
retina
photoreceptor cells very sensitive to light.
they enable us to see shades of gray in dim lights
rods
photoreceptor cells responsible for high acuity color vision. they only operate in bright lights red green blue
cones
synapse with dendrites of rods and cones.
they transmit nerve impulses to the ganglion cells
bipolar neurons
synapse with the axons of the bipolar neurons.
the axons combine to form optic nerve, which sends nerve impulses to the brain
ganglion cells
where the optic nerve leave the eye. not covered by the retina.
a blind spot in the eye
optic disc
cranial nerve II: it transmits visual information from the eye to the brain
optic nerve
the portion of the retina that is responsible for sharp central vision. humans use this region for any activity that requires detailed vision, such as driving
fovea centralis
