5 homeostasis - the eye Flashcards
1
Q
the iris reflex - bright and dim light
A
BRIGHT LIGHT
- circular muscles contract and radial muscles slacken
DIM LIGHT
- the opposite
2
Q
what happens to the eye when you look at things CLOSE UP
A
- ciliary muscles contract and suspensory ligaments slacken
- lens become converged and thick
- more light refracted
3
Q
what happens to the eye when you look at things FAR AWAY
A
- ciliary muscles relax and suspensory ligaments contract
- lens goes thin
- decreases refracted light
4
Q
long sited
A
HYPEROPIA
- your lens wont refract enough light
- light focuses behind the retina
- convex lens treats this
5
Q
short sited
A
MYOPIA
- your lens refracts too much light
- light focuses infront of the retina
- concave lens treats this
6
Q
CONTACT LENSES
A
- sit on the surface of the conea
- focus and refract light
- light weighted and invisible, and convenient
7
Q
LASER EYE SURGERY
A
vaporises tissue which changes shape of the cornea
8
Q
REPLACEMENT LENS SURGERY
A
best for long sited ppl
articifal lens replaces natural lens
