Visual System

Question 1

What is the cornea

Answer 1

A transparent protective tissue that is located at the front of the eye

Question 2

What is the iris

Answer 2

Round colored part of the eye that regulates the size of the pupils thus regulating the amount of light that enters

Question 3

What does the pupil do

Answer 3

Allow light into the eye

Question 4

What do cone cells do

Answer 4

Identifies color, 1:1 ratio for cone to neuron cells, produces lodosin

Question 5

What are rod cells

Answer 5

Identifies shapes and silhouettes, have a poor visual acuity and poor color response though, 10:1 ratio to neuron cells

Question 6

What is the fovea centralis

Answer 6

Contains only cone cells and provides day vision, allows for sharp 20/20 vision

Question 7

What is considered a blind spot

Answer 7

Where the optic nerve sits there are no rods or cones there

Question 8

What degrees is the day blind spot

Answer 8

5.5-7.5 degrees

Question 9

What degrees is the night blind spot

Answer 9

5-10°

Question 10

What component of the eye contains rods and cones

Answer 10

Retina

Question 11

*What chemical lets you see black white and gray

Answer 11

Rhodopsin

Question 12

*What is the function of the pupil when looking at an object

Answer 12

Pupil allows light to enter the eye and stimulate the retina

Question 13

What is an astigmatism

Answer 13

Due to unequal curvature if the cornea you can not focus on vertical and horizontal features at the same time

Question 14

Glare disability

Answer 14

Inability to detect objects against varying shards or backgrounds related to contrast

Question 15

People with myopia

Answer 15

Have near sighted ness

Question 16

Hyperopia

Answer 16

Farsightedness

Question 17

What is presbyopia

Answer 17

Hardening of lens, loss of elasticity and cataracts

Question 18

What are the types of corneal surgical procedures

Answer 18

LASIK PRK and LASEK

Question 19

What surgical procedure is less likely to cause damage due to the thinness of the flap

Answer 19

LASEK

Question 20

What is the condition result of blinded focal point behind renal plan or wall causing blurred vision (near objects are not seen well)

Answer 20

Hyperopia farsightedness

Question 21

What is it called when lens becomes less elastic over time

Answer 21

Presbyopia

Question 22

What are the three types of vision

Answer 22

Photopic, mesopic, scotopic

Question 23

What is photopic vision

Answer 23

Daylight, central vision, color Spence and image is sharp, 20/20 vision

Question 24

Mesopic vision

Answer 24

Transition day to night, dawn dusk moon light, use of parafoveal region (rods and cones), decreased visual acuity and color sense

Question 25

What should you do during Mesopic vision

Answer 25

Use increased scanning, no hoist

Question 26

What is scotopic vision

Answer 26

Night vision, peripheral vision (rods only), acutely degraded to silhouette recognition, loss of color perception, off center view technique

Question 27

What type of vision is the most dangerous

Answer 27

Mesopic vision

Question 28

Typed of monocular cues (GRAM)

Answer 28

Geometric, Retinal, Aerial, Motion

Question 29

What monocular cue is most important for depth perception

Answer 29

Motion parallax

Question 30

What is geometric perspective

Answer 30

Objects have different shapes when viewed at different angles Farther you are from an object the less detail there is compared to if you were closer

Question 31

Geometric Perspective - LAV

Answer 31

- Linear perspective - Apparent Foreshortening - Vertical Position in the field

Question 32

Retinal Image Size - KITO

Answer 32

- Known Size - Increasing/decreasing size - Terrestrial association - Overlapping contours

Question 33

How can you use terrestrial association

Answer 33

Compare one object to another object that you know the size off can help one estimate the size of the object you don't know that size of

Question 34

Aerial Perspective - FLP

Answer 34

- Fading - Loss of detail - Position of light source

Question 35

What are the two aspects of motion parallax

Answer 35

Stationary objects and observing moving Rate depends on relative distance of the object from the observer

Question 36

What are some limitations for night vision

Answer 36

Loss of depth perception, loss of visual acuity, night blind spots, dark adaption, color perception, night myopia, visual cues

Question 37

What is dark adaptation time

Answer 37

30-45 min time it takes for eyes to adjust from rods to cones

Question 38

Two most important monocular factors

Answer 38

Motion parallax Retinal image size

Question 39

At night what is the best visual city you can get

Answer 39

20/200

Question 40

With NGV at night what's the best you can see

Answer 40

20/40

Question 41

What vitamin helps with production of rhodopsin

Answer 41

A

Question 42

What is night myopia

Answer 42

Blue wavelength pervades in visible position causes this

Question 43

What are four examples of flight hazards

Answer 43

- Solar flare - Birds - Lasers - Nerve agents

Question 44

What are active ways to protect against lasers

Answer 44

Counter measures, evasive action scanning with one eye

Question 45

What are some passive ways to protect against lasers

Answer 45

Take cover, squint, goggles