Manual: Eyesight and Visual Illusions

Question 1

Each eye is connected to the brain by an ……. nerve.

Answer 1

optic

Question 2

To look at a near object, the eyes have to turn slightly (inward/outward).

Answer 2

inward

Question 3

The natural focal point for the eyes when resting is about (1 to 2 meters/ 20 meters/200 meters/infinity). This is referred to as ….. ….. myopia.

Answer 3

1 to 2 meters, empty field

Question 4

A person with only one eye (will/will not) have protection from the blind spot.

Answer 4

will not

Question 5

A person with two eyes (does/does not) have blind spots. The second eye (does/does not) provide protection.

Answer 5

does, does

Question 6

Focusing both eyes on the one object is called ……. vision, and it (helps/ does not help) with depth perception.

Answer 6

binocular, helps

Question 7

The transparent cap over the lens of each eye is called the ……. .

Answer 7

cornea

Question 8

The cornea can be protected by the ….. closing over it.

Answer 8

eyelid

Question 9

The colored membrane between the cornea and the lens is called the ….. , and it contains a small, round aperture called the ….. which (can/cannot) change in size.

Answer 9

iris, pupil, can

Question 10

in bright light, the pupil will e (small/wide); in dim conditions, the pupil will be (small/wide).

Answer 10

small, wide

Question 11

The part of the eye that can change shape and does most of the focusing of the lights rays is the …. . The greater its curvature, the (greater/lesser) the focusing.

Answer 11

lens, greater

Question 12

The ability of an eye to change its focus point is called ………. .

Answer 12

accommodation

Question 13

The lens should focus the incoming light rays on the light-sensitive layer at the back of the eye, known as the …… .

Answer 13

retina

Question 14

The central section of the retina consists mainly of …….. cells which (are/are not) sensitive to color, (are/are not) sensitive to small details, (are/are not) sensitive to distant objects, and are most effective in (daylight/darkness).

Answer 14

cones, are, are, are, daylight.

Question 15

The peripheral, outer region of the retina consists mainly of …… cells which (are/are not) sensitive to color, and (are/are not) sensitive to small details, and (are/ are not) sensitive to distant objects and are most effective in (daylight/darkness).

Answer 15

rod, are not, are not, are not, both daylight and darkness.

Question 16

The blind spot in each eye is where the …. nerve leaves the retina.

Answer 16

optic

Question 17

the ability to see clearly and sharply is called visual …… .

Answer 17

acuity

Question 18

Visual acuity (is/is not) diminished by fatigue or alcohol.

Answer 18

is

Question 19

In strong sunlight or glary conditions you should wear …….. .

Answer 19

sunglasses

Question 20

Depth perception when landing is (easier/more difficult) in hazy or foggy conditions.

Answer 20

more difficult

Question 21

On approach in hazy conditions, the runway way be (closer/further away) than what is appears to be, often causing pilots to flare too (early/late).

Answer 21

closer, late

Question 22

Men are (more/less) likely then woman to have some form of color-blindness.

Answer 22

more

Question 23

The eyes take about .. minutes to adapt to darkness. The most effective retinal cells in darkness are the (rods/cones) which are used for (peripheral/central) vision.

Answer 23

30 minutes, rods, peripheral

Question 24

Bright light in the cockpit at night can destroy light adaption (immediately/ after about 5 minutes), and it then takes about .. minutes to re-establish full light adaption.

Answer 24

immediately, 30 minutes.

Question 25

When scanning for aircraft by day, you should use your (central/peripheral) vision.

Answer 25

central

Question 26

When scanning for aircraft by night, you should use your (central/peripheral) vision.

Answer 26

peripheral

Question 27

The resting eye sources at about ….. meters; this is known as e…… f…… m…… , so we (do/do not) have to concentrate on focusing on distant aircraft.

Answer 27

1 to 2 meters, empty field myopia, do

Question 28

The visual illusion of a single station-ary light at night appearing to move is called ……. .

Answer 28

autokinesis

Question 29

Sloping cloud banks by day or town lights at night appearing to move is called …….. .

Answer 29

can

Question 30

The normal approach path to a runway sloping upwards will appear to be too (steep/shallow), causing a tendency for an inexperienced pilot to fly too (high/low) on slope.

Answer 30

steep/low

Question 31

The normal approach path to a runway sloping downwards will appear to be too (steep/shallow), causing a tendency for an inexperienced pilot to fly too (high/low) on slope.

Answer 31

shallow, high

Question 32

An especially wide runway will appear to be (closer/further) away than it really is during the late stages of an approach, causing a tendency for an inexperienced pilot to flare too (high/low).

Answer 32

closer, high

Question 33

An especially narrow runway will appear to be (closer/further away) than it really is during that late stages of an approach, causing a tendency for an inexperienced pilot to flare too (high/low).

Answer 33

further away, low

Question 34

During a night approach, the apparent gap between the runway edge lights is increasing. The aeroplane is flying to an aiming point (before/at/beyond) the normal aiming point.

Answer 34

beyond

Question 35

During a night approach, the apparent gap between the runway edge lights is decreasing. The aeroplane is flying to an aiming point (before/at/beyond) the normal aiming point.

Answer 35

before

Question 36

It is (good/poor) airman ship to use a v……. a….. s…… i…… at night.

Answer 36

good, visual approach slope indicator.

Question 37

An approach at night to a well-lit runway, but with no lights to be see is called a …… - ….. approach.

Answer 37

black-hole

Question 38

The lack of features near a runway, say during a back-hole approach or in a white-out snow conditions , make depth and slow perception (more/less) difficult.

Answer 38

more

Question 39

The term myopia refers to (long/short) sightedness.

Answer 39

short

Question 40

A short-sighted eye focuses the light rays (too much/ not enough).

Answer 40

too much

Question 41

A long-sighted eye focuses the light rays (too much/ not enough).

Answer 41

not enough

Question 42

Short-sightedness is called ……. ; long-sightedness is called …….. or ……… .

Answer 42

myopia, hyperopia or hypermetropia

Question 43

Reading becomes more difficult with age because the eyes become more (long-/short-)sighted, known as ………. . It causes diminished (near/far) vision, and is often corrected by using (full-/half-)glasses.

Answer 43

long-sighted, presbyopia, near, half-glasses

Question 44

Faulty curvature of the lens is called …….. .

Answer 44

astigmatism

Question 45

If glasses are required for flying, you should carry (one/two/three) pairs.

Answer 45

two

Question 46

What do Rods do?

Answer 46

Rods are responsible for vision at low light levels (scotopic vision). They do not mediate color vision, and have a low spatial acuity.

Question 47

What do Cones do?

Answer 47

Cones are active at higher light levels (photopic vision), are capable of color vision and are responsible for high spatial acuity. The central fovea is populated exclusively by cones. There are 3 types of cones which we will refer to as the short-wavelength sensitive cones, the middle-wavelength sensitive cones and the long-wavelength sensitive cones or S-cone, M-cones, and L-cones for short.