The Visual System

Question 1

Name the major components of the human eye

Answer 1

• Cornea
• Iris
• Pupil
• Lens
• Retina

Question 2

The _________ is the transparent protective tissue located over the front of the eye

Answer 2

Cornea

Question 3

Iris

Answer 3

Round pigmented membrane that adjusts the amount of lights that enters the eye

Question 4

The _______ is the opening in the center of the iris. It allowa light to enter the eye.

Answer 4

Pupil

Question 5

The _______ is a transparent, biconvex membrane that directs light rays entering the pupil upon the retina.

Answer 5

Lens

Question 6

Retina

Answer 6

Thin multi-layered membrane which covers most of the posterior compartment of the eye, contains the photoreceptors

Question 7

What two types of photoreceptor cells are located in the retina?

Answer 7

Cones and Rods

Question 8

Where are Cones located within the retina

Answer 8

Located in Fovea Centralis and parafovea region

Question 9

What are the functions/qualities of Cone cells?

Answer 9

Respond selectively to colors, sharp detals, allows for daytime vision.

Question 10

Where are Rods located within the retina

Answer 10

Located in peripheral region and parafovea region

Question 11

What are the functions/qualities of Rod cells?

Answer 11

very sensitive to low light levels, allows for night vision, poor acuity; detects movement, and edges/lines. Not color sensitive, shades of gray/”purple”

Question 12

Where is the day blind spot and how many degrees does it cover?

Answer 12

Located in the optic disk because it contains no receptor cells (also blind at night).

Covers 5.5 to 7.5 degrees

Question 13

Where is the Night blind spot and how many degrees does it cover?

Answer 13

Located in the Fovea Centralis area because it contains no Rods.

Covers 5 to 10 degrees of the field of vision.

Question 14

Astigmatism

Answer 14

Unequal curvature or irregularities in the cornea or lens that create multiple focal points in the anterior chamber

Question 15

Myopia

Answer 15

nearsightedness; far objects are blurry

Question 16

Hyperopia

Answer 16

farsightedness; near objects are blurry

Question 17

Presbyopia

Answer 17

“old eyes”; due to hardening of the lens that occurs naturally with age; both near and far objects appear blurry; need bi-focals

Question 18

Types of approved corrective eye surgery

Answer 18

PRK, LASIK, and LASEK

Question 19

Types of vision

Answer 19

P.M.S. Photopic Mesopic Scotopic

Question 20

Photopic

Answer 20

Day vision

Question 21

Mesopic

Answer 21

Dusk/dawn; full moon, twilight vision

Question 22

Scotopic

Answer 22

Night vision; partial moon or starlight

Question 23

Which type of vision is considered the most dangerous for Aviation

Answer 23

Mesopic

Question 24

Cues to distance estimation and depth perception (2 types)

Answer 24

Binocular and Monocular

Question 25

Monocular

Answer 25

Visual cues from one eye

Question 26

Binocular

Answer 26

Visual cues from two eyes

Question 27

Which type of cue is more important in aviation (monocular or binocular)

Answer 27

Monocular

Question 28

What is the acronym for the monocular cues for depth perception

Answer 28

G.R.A.M.

Question 29

Expand the acronym G.R.A.M

Answer 29

Geometric Perspective Retinal image size Aerial perspective Motion Parallax

Question 30

Types of Geometric Perspective L.A.V.

Answer 30

Linear Perspective Apparent Foreshortening Vertical position in the field

Question 31

Types of Retinal image size K.I.T.O.

Answer 31

Known size of objects Increasing or decreasing size of objects Terrestrial association Overlapping Contours

Question 32

Types of Aerial Perspective F.L.P.

Answer 32

Fading of colors and shades Loss of textures and detail Position of light source

Question 33

What is the MOst important of the MOnocular cues

Answer 33

MOtion parallax

Question 34

\_\_\_\_\_\_\_ compensates for the night blind spot?

Answer 34

Scanning

Question 35

An unequal curvature of the cornea resulting in the inability of the eye to focus on multiple objects simultaneously in the horizontal and vertical planes is called?

Answer 35

Astigmatism

Question 36

What is the proper name for nearsightedness?

Answer 36

Myopia

Question 37

What is the proper name for farsigthedness?

Answer 37

Hyperopia

Question 38

This occurs with the aging process and results in the hardening of the lens?

Answer 38

Presbyopia

Question 39

Vitamin A is required for the production of?

Answer 39

Rhodopsin

Question 40

The apparent relativ motion of stationary objects as viewed by a moving observer is?

Answer 40

Motion Parralax

Question 41

Average time to dark adapt is ____ - _____ minutes for a well rested aviator

Answer 41

35 - 40