Visual systems

Question 1

Which cells in the eye are used in periods of bright light ?

Answer 1

Cone cells

Question 2

What does cone cells do ?

Answer 2

Identify colors

Question 3

How many
cone cells & Rod cells
are there in relation to neuron cells ?

Answer 3

1:1 cone cells
10:1 - 10.000:1 rod cells

Question 4

Which cells are used in periods of low light and darkness ?

Answer 4

Rod cells

Question 5

What’s the eyes two blind spots called and how many degrees do they encompass ?

Answer 5

Day blind spot: 5.5-7.5º
Night blind sport: 5-10º

Question 6

What component of the eye contains the photoreceptors “rods & cones” ?

Answer 6

The retina

Question 7

What’s the chemical that allows us to see black, white and grey colors at night ?

Answer 7

Rhodopsin

Question 8

What’s the function of the pupil when looking at an object ?

Answer 8

The pupil allows light to enter the eye and stimulate the retina

Question 9

Name the 4 visual deficiencies

Answer 9

Astigmatism
Myopia
Hyperopia
Presbyopia

Question 10

What happens to a person if they have Astigmatism

Answer 10

Blurry vision

Can’t focus on vertical and horizontal features at the same time

Question 11

What’s myopia and how is it experienced ?

Answer 11

Nearsightedness

blurry vision when viewing image at a distance

focal point is infront of retina

Question 12

What’s Hyperopia and how is it experienced ?

Answer 12

Farsightedness

blurry vision when viewing image that are nearby

focal point is behind retina

Question 13

What’s presbyopia ?

Answer 13

Aging og the eye - hardening of the lense

Hard to focus on things nearby

Can result in glare disability (contrast sensitivity)

Question 14

Which 3 corneal refractive surgeries are allowable in the army aviatio ?

Answer 14

PRK, LASIK, LASEK

(Has to consult flight surgeon beforehand)

Question 15

Name the 3 types of vision + what they are for?

Answer 15

- Photopic vision
Daylight/bright light
- Mesopic vision
Dawn, dusk (bright nights - full moon)
- Scotopic vision
Night vision

Question 16

Which of the 3 vision types brings the most challenges to crewmembers ?

Answer 16

not sure

Mesopic vision
(night vision - twillight)

Question 17

What is considered the most important cue (GRAM) to depth perception ?

Answer 17

Motion parallax

Driving a moving car - Things closer to you appears to move faster then things further away - Use to determine how close things are to you, based on how fast objects are moving

Question 18

Name the binocular cue

Answer 18

Retinal disparity

Different view of an image between each eye

Question 19

Name the monocular cues

Answer 19

GRAM
Geometric perspective
Retinal image size
Aerial perspective
Motion parallax

Question 20

What is the avarage time required for dark adaptation ?

Answer 20

30-45 minutes

Question 21

Name 4 visual illutions

Answer 21

FFSS
Fication
False horizon
Structural illusion
Size distance illusion

Question 22

Name some limitations of night vision

Answer 22

• Depth perception
• Night blind spots
• Color perception
• Dark adaptiation time
• Visual cues
• Visual acuity ( obstacle identification )

Question 23

Which of the self-imposed stresses (DEATH) can result in hypemic hypoxia ?

Answer 23

Tobacco use

Question 24

Which surgical procedure is less likely to cause permanent vision change (due to thinness of the flap) ?

Answer 24

LASEK

Question 25

Which of the self-imposed stresses (DEATH) can result in crewmembers not scanning just staring ?

Answer 25

Alcohol