the brain and the eye Flashcards
1
Q
How does the eye respond to dim light
A
radial muscles contract
circular muscles relax
dilated pupil (so more light enters eye)
1
Q
How does the eye respond to bright light
A
- radial muscles relax
- circular muscles contract
- contracted pupil (less light enters eye)
2
Q
How does the eye respond to an object far away
A
- ciliary muscles relax
- suspensory ligaments tighten
- lens because thinner and longer meaing the light is refracted less
3
Q
How does the eye respond to an object close by
A
- ciliary muscles contract
- suspensory ligaments -slacken
- lens because fatter
4
Q
What is myopia
A
short-sightedness
- lens is too thick and curved
- meaning light refracts to much and image is in focus in front of the retina
- eyeball is too elongated
5
Q
What lens is used to correct short-sightedness
A
concave lens corrects rays by making them refract less so they focus on the retina
6
Q
What is hyperopia
A
long-sightedness
- image is brought into focus behind the retina
- eyeball is too short and fat
7
Q
How is hyperopia corrected
A
- convex lens refracts light rays more so that they focus on the retina
