Eye Flashcards
conjunctiva
protective layer front
cornea
transparent layer front
iris
controls pupil aptiture
aqueous humour
between cornea and lens
lens
refracts light on to retina
ciliary muscle
accommodation
sclera
protective layer around most
virtuous humour
liquid centre
blind spot
no light receptor cells
fornea
high amount of cones
retina
of light sensitive cells back
light refracted at cornea and humour to focus on retina, light sensitive cells stimulated, optic nerve sends sensory neuron impulses to brain, brain interprets image correct way up
process of image production
accommodation
eye’s ability to focus on objects at different distances by changing shape of lens
what happens when light is dim?
radial muscles contract, circular muscle relax, pupils dilate
what happens when light is bright?
radial muscle relax, circular muscle contract, pupils constrict
distant objects
ciliary muscles relax, ligament tight, lens thin, less strong refraction
close objects
ciliary muscles contract, ligament relax, lens thick, more strong refraction
myopia (short sightedness)
rays focus prior to hitting retina, eyeball too long, lens too round
hyperopia (long sightedness)
rays focus after retina, eyeball too short, retina too short + thin
concave lens
myopia, diverges rays to converge on retina
convex lens
hyperopia, curved so rays converge on retina
laser eye surgery
decrease cornea thickness so less strong refraction on distant light (myopia), change cornea curve so more efficient refraction on close light (hyperopia)
