The Eye Flashcards
what is the eye
a sensory receptor that detects light
what structures in the eye focus light
cornea and lens
what is the hole in the eye where light enters cold
pupil
what is the retina
the back of the eye where light is focused, has special receptor cells called rods and cones to detect light changes
what is the name of the nerve in the eye
the optic nerve
what 2 things control the lens shape
suspensory ligaments
ciliary muscles
what shape will the lens be to focus on a nearby object
fat and round
what shape will the lens be to focus on far object
thin
what happens to the muscles and ligaments in the eye to make the lens fat and round
ciliary muscles - contracted
suspensory ligaments - slack
what happens to the muscles and ligaments in the eye to make the lens fat thin
ciliary muscles - relaxed
suspensory ligaments - tight
what do cones detect
sensitive to bright lights and colours
what do rods detect
sensitive to low lights and respond to how dark or light something is
what are 4 eye problems
cataracts
colour blindness
long sight
short sight
what is a cataract
occurs when the lens becomes cloudy so light cannot properly pass-through
what is a way to treat cataracts
artificial lens
what is colour blindness
occurs when some types of cone cells are not working
why is colour blindness an inherited disease that is mostly in males
it is because it is passed on through the X chromosome
what is long-sightedness
when a person can’t see things close to them
this is because the lens cannot focus the light enough so the image forms behind the retina
what is long-sightedness
when a person can’t see things far away from them
this is because the lens focuses the light too much so the image forms in front of the retina
what lens is used to fix long-sightedness
converging
what lens is used to fix short-sightedness
diverging
