the eye Flashcards
what happens when your eye detects very bright light ?
-circular muscles contract
-radial relax
which reduces the amount of light getting in
what happens in dim light?
-circular muscles relax
_radial contract
which makes pupils wider to allow more light in
what happens in your eye when you look at near objects ?
-cillary muscles contracts
-suspensory ligaments relax
-lens becomes more fat
therefore refraction increases
what happens when you look at distant objects?
-cillary relax
-suspensory ligaments contract
-lens thin less curved
therefore refraction decreases
what happened to the image if you are longsighted?
-images near objects are bought into focus behind the retina
what lens do you have to use for glasses being long sighted + function?
- convex
- refracts the light rays so they are focused on the retina
role of cornea ?
refracts light into the eye
role of iris ?
controls how much light gets into the eye
role of lens?
focuses light on the retina
definition of being long sighted ?
unable to focus on near objects
medical term for being long sighted ?
hyperopia (eye man)
definition of short sighted ?
unable to focus on distant objects
medical term for short sightedness ?
Myopia
role of the optic nerve ?
-carries impulses fro the receptors on the retina to the brain
role of sclera ?
tough supporting wall if the eye
