The eye Flashcards
what is the cornea
transparent layer that refracts light
what is the pupil
gap that allows light to the lens
what type of cells are in the retina
cone and rod
where does light focus on the retina
fovea
what two muscles are in the iris reflex
radial and circular
what does the lens do
refracts by changing shape
what does the iris do
controls how big or small the pupil is
what happens when your eyes are exposed to bright light
pupil constricts so the retina is not damages
circular muscles contracts
radial muscle relaxes
what happens when your eyes need more light
pupil dilates to allow more light
circular muscle relaxes
radial muscles contract
features of the eye (6)
iris
lens
cornea
pupil
optic nerve
retina
what is accommodation
a reflex that changes refractive power of the lens
what happens to the eye when the objects close
the eye needs to be short and fat in order to refract more so the ciliary muscles contract and suspensory ligaments slackens
what happens to the eye when the objects far
the eye doesn’t need to refract as much so the eye is tall and thin so ciliary muscles relaxes and suspensory ligaments are taut
what is long sightness called
hyperopia
what is short sightness called
myopia
