vision

Question 1

when focusing on an object w/in 20 feet what 2 things happen

Answer 1

1. ciliary body causes the lens to bulge

2. iris constricts the pupil

Question 2

what is near point of vision

Answer 2

how close up you can focus on object/ how well our lens can bulge

Question 3

near point of vision at

1. 18 years old
2. 40 years old
3. 50 and older

Answer 3

1. four inches from eye
2. eight inches from eye
3. 16 inches from eye

Question 4

when focusing on an object more than 20 feet away what 2 things happen

Answer 4

1. ciliary body causes the lens to flatten

2. iris dilates pupil

Question 5

cataract

1. most what
2. what is it
3. treatment
4. four risk factors

Answer 5

1. most common cause of blindness
2. clouding of lens
3. treated w/ surgery
4. UV exposure, diabetes, smoking, old age

Question 6

glaucoma

1. second what
2. due to what
3. causes what
4. three risk factors

Answer 6

1. second leading cause of blindness
2. due to buildup of aqueous humor
3. increases pressure w/in eyeball that damages the retina
4. high blood pressure, smoking, family history

Question 7

macular degeneration

1. third what
2. what happens
3. two risk factors

Answer 7

1. third leading cause of blindness
2. macula lutea cells die off
3. smoking, old age

Question 8

nearsightedness

1. caused by
2. what is too far from what
3. what can and can’t you see

Answer 8

1. eyeball is oblong from front to back
2. macula lutea is too far from lens
3. can see close up but not far

Question 9

farsightedness

1. caused by
2. what is too close to what
3. what can and can’t you see

Answer 9

1. eyeball is oblong top to bottom
2. macula lutea is too close to lens
3. can see far but not close

Question 10

astigmatism

1. caused by
2. results in what

Answer 10

1. irregular curvature of cornea and/or lens

2. a portion of visual field to be out of focus

Question 11

color blindness

1. what is it
2. most common type
3. caused by
4. percentage of men who have it

Answer 11

1. inability to distinguish between 2 colors
2. red-green color blindness
3. due to lack of one of the cone types
4. 10 percent

Question 12

photoreceptor adaptation for cones

when it’s dark and all of a sudden bright what do the cones do

Answer 12

each cone type will quickly and independently downregulate

Question 13

photoreceptor adaptation for cones

when it’s bright and all of a sudden dark what do the cones do

Answer 13

the cones upregulate

Question 14

photoreceptor adaptation for cones

when it’s bright and all of a sudden dark except for one specific color you’re staring at what do the cones do

Answer 14

each cone type will upregulate independently