Principles of Night Vision and NVG Driving

33
Action: Discuss the Principles of Night Vision, NVG
General Characteristic.
Condition: In the classroom setting we will discuss,
Principles of Night Vision, NVG General
Characteristic, AN/PVS-5, AN/PVS-7 NVG
and Driving Techniques/Procedures
Standard: Discuss IAW TC 21-305-2 Training Program
for Night Vision Goggle Driving Operations,
FM 21-305 Manual for Wheeled Vehicle
Driver, & AR 600-55 The Army Driver and
Operator Standardization program
ENABLING LEARNING OBJECTIVE: # 6ENABLING LEARNING OBJECTIVE: # 6

44
INTRODUCTION:INTRODUCTION:
 This lesson is designed for familiarization purposes
only, and it is not included in the final written
examination. However, a quiz is to be administered.
Although not critical for accomplishing the objective
of the course. (Student should have a working
knowledge of the basics of vision/night vision before
receiving and applying any instruction on night vision
goggles).

55
VISIONVISION
 This is the most important sense you use whileThis is the most important sense you use while
driving. It is the sense that makes you aware of thedriving. It is the sense that makes you aware of the
position of your vehicle in relation to the road. Youposition of your vehicle in relation to the road. You
need good dept perception for determining heightneed good dept perception for determining height
and distance, good visual acuity for identifyingand distance, good visual acuity for identifying
terrain features and obstacles, And good night visionterrain features and obstacles, And good night vision
techniques for efficiency in night operations.techniques for efficiency in night operations.

66
NIGHT VISION GOGGLE DRIVING OPERATIONSNIGHT VISION GOGGLE DRIVING OPERATIONS
Night OperationsNight Operations
Depth Perception Height and Distance
Visual Acuity Terrain Features &
Obstacles
Night Vision Techniques Effective Night
Operations

77
Anatomy of the EyeAnatomy of the Eye
1. The CORNEA is the clear, protective part of the eye that
covers the iris and pupil

88
2. The IRIS is the colored portion of the eye

99
3. The PUPIL is a hole in the center of the iris. The size of
the pupil varies with the amount of light entering the eye.
That is, it gets smaller with increase

1010
4. The LENS can change shape to focus on objects at
different distances from the eye.

1111
5. The RETINA is the lining at the back of the eye where the
image is formed. The picture seen by the retina is sent to
the brain along the optic nerve.

1212
HOW THE EYE WORKS:HOW THE EYE WORKS:
 LIGHT ENTERS YOUR EYE THROUGH THELIGHT ENTERS YOUR EYE THROUGH THE
PUPIL. THE AMOUNT OF LIGHT ENTERINGPUPIL. THE AMOUNT OF LIGHT ENTERING
THE EYE IS CONTROLLED BY THE IRIS. THETHE EYE IS CONTROLLED BY THE IRIS. THE
LIGHT PASSES THROUGH THE LENS, WHICHLIGHT PASSES THROUGH THE LENS, WHICH
FOCUSES IT ONTO THE RETINA AT THE BACKFOCUSES IT ONTO THE RETINA AT THE BACK
OF THE EYE. THE PICTURE SEEN BY THEOF THE EYE. THE PICTURE SEEN BY THE
RETINA IS UPSIDE DOWN AND THE BRAINRETINA IS UPSIDE DOWN AND THE BRAIN
TURNS IT RIGHT WAY UPTURNS IT RIGHT WAY UP

1313
VISUAL ACUITYVISUAL ACUITY
 THIS IS HOW WELL YOU SEE. IT ISTHIS IS HOW WELL YOU SEE. IT IS
DETERMINED FOR EACH EYE BY READING ADETERMINED FOR EACH EYE BY READING A
STANDRD EYE CHART. A SHORT HANDSTANDRD EYE CHART. A SHORT HAND
NOTATION RECORDS ACUITY, WITHNOTATION RECORDS ACUITY, WITH
NORMAL RECORDED AS 20/20NORMAL RECORDED AS 20/20

1414
Types of VisionTypes of Vision
NVG VGT 13
MESOPIC
PHOTOPIC
SCOTOPIC
DAYLIGHT HOURS or
when a high level artificial
light exists
DAWN, DUSK, MID-LIGHT
levels a reduction in color
vision and visual acuity occurs
as the light level decrease
NIGHTIME HOURS visual
acuity decreases to 20/200 or
less and total loss of color
vision

1515
VISUAL PROBLEMSVISUAL PROBLEMS
AFFECTING NIGHT VISIONAFFECTING NIGHT VISION
• PRESBYOPIA
• NIGHT MYOPIA
• ASTIGMATISM

1616
PRESBYOPIAPRESBYOPIA
 The inability of the eye to focus sharply on nearby
objects, resulting from hardening of the lens.
PRESBYOPIA is common in individuals over 40
years of age. This can be corrected with certain
types of bifocal lenses.

1717
NIGHT MYOPIANIGHT MYOPIA
 A visual defect in which distant objects appear
blurred because their images are focused in front
of the retina rather than on it; nearsightedness.
Special lenses can be prescribed to correct this.

1818
ASTIGMATISMASTIGMATISM
 A refractive defect of the lens that prevents
focusing of sharp, distinct images. For example,
if you focus on power poles, the wires will be out
of focus in most cases. Your horizontal and
vertical focusing is not equal. It can be corrected
with prescription eye glasses.

1919
DARK ADAPTATIONDARK ADAPTATION
 This is the process by which your eyes increase
their sensitivity to low light levels. Maximum
dark adaptation is reached in about 30-45 minutes.
Exposure to a flare or lightning may require 5-45
minutes for night vision recovery. It takes about
2 minutes to return to dark adaptation after using
NVG’S.

2020
NIGHT TACTICAL PRECAUTIONS
• Avoid areas of high intensity light.
• Never use your headlights or 4-way flashers.
• Know your route.
• Quickly warn other traffic in cases of emergency
by using your tactical flashlight or Chem-light.
• Understand the limitations and capabilities of the
NVG’S. THIS IS THE KEY TO HANDS ON
TRAINING.

2121
Self-Imposed StressesSelf-Imposed Stresses
NVG VGT-04
1. Smoking
2. Alcohol
3. Fatigue
4. Nutrition
5. Physical Condition
6. Sleep

2222
• Smoking: The smoker effectively reduces his/her night
vision ability by 20%
• Alcohol: This impairs both coordination and judgment.
• Fatigue: When you tired, you are not mentally alert;
fatigue will slow down your response to night situations
that require immediate reaction.
• Nutrition: Hunger pains lead to distraction and a
shortened attention span. Failure to eat foods that provide
sufficient vitamin A (eggs, cheese, carrots) can reduce night
vision.

2323
• Physical Conditioning: You should exercise daily.
Good physical conditioning will help you conduct night
driving with less fatigue. However, too much exercise
in a given day may leave you too tired.
• Sleep: Night driving is more tiring and stressful than
day driving. Therefore, it is important to get enough rest
before driving.

2424
Night Vision Scanning TechniquesNight Vision Scanning Techniques
Are important in object identification at night. Scan from right to left
or right to left, using a slow regular scanning movement.

2525
IDENTIFICATION BY SHAPE:IDENTIFICATION BY SHAPE:
 Because your visual acuity is greatlyBecause your visual acuity is greatly
reduced at night, Objects must be identifiedreduced at night, Objects must be identified
by their shape or outline. Being familiarby their shape or outline. Being familiar
with the architectural design of structureswith the architectural design of structures
common to your area will help.common to your area will help.

2626
Depth PerceptionDepth Perception
NVG VGT-25
The quality of seeing objects as
three-dimensional solids in space.
 This aids the quality of seeing objects as three-
dimensional solids in space. Perhaps it gave our tree-
dwelling forefathers an edge when they swung from branch
to branch. They knew exactly where in the space that next
branch was located.

2727
Distance Estimation/Depth PerceptionDistance Estimation/Depth Perception
NVG VGT-26

2828
Sources of Ambient LightSources of Ambient Light
NVG VGT-27
• The Moon
• Background Lighting
• Artificial Lights
• Solar Lights
• Lasers

2929
1. MOON:1. MOON: The moon provides the greatest source ofThe moon provides the greatest source of
ambient light at night. Light from the moon isambient light at night. Light from the moon is
brightest when the moon is at its highest point in thebrightest when the moon is at its highest point in the
sky.sky.
2. BACKGROUND LIGHTNING:2. BACKGROUND LIGHTNING: Besides the moon,Besides the moon,
other natural light sources contribute to nightother natural light sources contribute to night
brightness, such as the aurora (northern lights in thebrightness, such as the aurora (northern lights in the
Northern Hemisphere) and starlight.Northern Hemisphere) and starlight.

3030
(Continued)(Continued)
3. ARTIFICIAL LIGHTS: Lights from cities, cars,
fires, and flares are sources of illumination.
4. SOLAR LIGHT: This light is usable for certain
periods following sunset and before sunrise.
5. LASERS: Lasers can affect the performance of
the naked eye or night vision devices.

3131
What are Night Vision GogglesWhat are Night Vision Goggles
NVG VGT-30
Night Vision Goggles are devices that make an object more
visible during periods of low light levels. Their performance
is directly related to the amount of light available, such as
starlight and moonlight.

3232
AdvantagesAdvantages
NVG VGT-31
Better view of the surrounding area and
object identification at night
NVG’S make it possible to:
Read
Patrol
Provide medical aid
Drive
Walk
Observe the enemy
At night
without the
help of lights

3333
DisadvantagesDisadvantages
NVG VGT-32
Performance is reduced in rain, haze, fog, snow
or smoke.
Visual acuity is reduced.
Limited field of view.
Reduced depth perception.
Overconfidence.
Focal range.

3434
GENERAL DISADVANTAGES:GENERAL DISADVANTAGES:
 NVG performance is reduced in rain, haze,NVG performance is reduced in rain, haze,
fog, snow, or smoke. Also, NVG do notfog, snow, or smoke. Also, NVG do not
magnify images viewed through the tubes. Anmagnify images viewed through the tubes. An
object viewed through the goggles at night willobject viewed through the goggles at night will
be the same size as if it were seen during thebe the same size as if it were seen during the
day without the goggles. Objects that areday without the goggles. Objects that are
difficult to see during the day with the nakeddifficult to see during the day with the naked
eye are also hard to detect at night with NVG.eye are also hard to detect at night with NVG.

3535
 NVG’S make an object more visible at
night by__________
A. Magnifying objects
B. Intensifying the amount of available
moonlight/starlight.
C. Using the NVG’S infrared light feature.
QUESTION:QUESTION:

3636
 The performance of NVG’S is directly
related to the amount of available light, such
as starlight and moonlight. However,
NVG’S are not affected by rain, haze, fog or
snow.
A. TRUE B. FALSE

3737
 A halo around artificial lights as seen
through the goggles is an indication of______
A. Visibility restrictions.
B. Low battery power.
C. A visual illusion.

3838
 How can drivers compensate for their
reduced field of view?
A.By understanding the principles of night
vision.
B. By understanding the limitations and
capabilities of the device.
C. By using a slow, continual scanning
pattern.

3939
Infrared IlluminatorInfrared Illuminator
The IR (INFRARED) ILLUMINATOR
makes the NVG an active system capable of
being detected by
THE THREAT.

4040
VIEWINGVIEWING
CHARACTERISTICCHARACTERISTIC
•The field of view with the NVG’S is 40 degrees,
compared to 200 degrees unaided.
• NVG’S decrease depth perception at distances
less than 20 feet or greater than 500 feet.
• The focal range of NVG’S is 10 inches to infinity.

4141
OVER CONFIDENCEOVER CONFIDENCE
 Overconfidence is a main fault associated with
NVG use. After wearing the device for only a
short time, you may feel you have complete visual
acuity and depth perception when in fact you do not.
The ability to drive with NVG’S is developed
through training. The more you drive with goggles,
the more you learn about them. As a result, you gain
confidence in your ability and the capability and
limitations of the device.

4242
QUESTION:QUESTION:
 The best range for depth perception and
distance estimation when wearing goggles
is less than 20 feet or greater than 500 feet.
A. TRUE B. FALSE

4343
The field of view as seen through the
goggles is limited to___________.
A. 30 degrees C. 45 degrees
B. 40 degrees D. 50 degrees

4444
The objective focus is used to focus on
objects from_______________.
A. 1 foot to infinity.
B. 10 inches to infinity.
C. 20 to 500 feet.

4545
General CharacteristicsGeneral Characteristics
NVG VGT-44
• Single-color Viewing
• Monochromatic Adaptation
• Dark Adaptation
• Spatial Disorientation

4646
SINGLE COLOR VIEWING:SINGLE COLOR VIEWING:
 All objects viewed through the NVG’S will
appear green. NVG’S do not provide for color
discrimination. As a result, it is difficult to
distinguish between certain objects or features.
Dark areas will appear black and light areas will
appear white. Shadows, for example, are difficult to
distinguish from puddles of water, walls ditches,
and vice versa when viewed through goggles at
night.

4747
MONOCHROMATIC ADAPTATION:MONOCHROMATIC ADAPTATION:
 MONOCHROMATIC ADAPTATION: (One
color) Adaptation happens upon reentering a high
ambient light environment after wearing the NVG
for an extended time. You may experience a tint
or discoloration of objects viewed with the
unaided eye. This is a normal physical reaction
that causes no discomfort and disappears in about
2 minutes.

4848
 DARK ADAPTATION: Under ideal conditions
(total dark adaptation before NVG use & removal
of NVG’S in a dark environment), you can expect
to regain full dark adaptation in about 2 minutes.
DARK ADAPTATIONDARK ADAPTATION

4949
 SPATIAL DISORIENTATION: Dizziness and
nausea may be caused by driving with one tube
focused inside the vehicle and the other focused
outside the vehicle when wearing the AN/PVS 5
series goggles. Use your assistant driver to help
you with objects inside the cab of the vehicle.
SPATIAL DISORIENTATIONSPATIAL DISORIENTATION

5050
 Amount of ambient light. During periods of
high ambient light, in a low light area, resolution
is improved and objects can be identified a
greater distances. Visual acuity (the accuracy
with which an object is seen) with NVG’S will
never be as good as it is with the naked eye
during daylight conditions. Again, NVG
performance is directly related to the

5151
QUESTION:QUESTION:
 Driving with one tube focused inside the
vehicle and the other outside is a condition
that causes____________.
A. Dark Adaptation
B. Spatial Disorientation
C. Motion Parallax

5252
Effects of LightEffects of Light
NVG VGT-51
• Vehicle Lighting
• Instrument Lighting
• Lasers
• Artificial Lights
• Ambient Light Level

5353
Tube DefectsTube Defects
NVG VGT-52

5454
AN/PVS-5 SERIES NVGAN/PVS-5 SERIES NVG
NVG VGT-53

5555
NVG VGT-54

5656
NVG VGT-55

5757
AN/PVS-7A SERIES NVGAN/PVS-7A SERIES NVG
NVG VGT-56

5858
AN/PVS-7A SERIES NVGAN/PVS-7A SERIES NVG
NVG VGT-57

5959
AN/PVS-7B SERIES NVGAN/PVS-7B SERIES NVG
NVG VGT-58

6060
AN/PVS-7B SERIES NVGAN/PVS-7B SERIES NVG
NVG VGT-59

6161
 Always remove the battery before storing
the goggles. When installing or removing
a battery, make sure the selector switch
is in the off position. If the rotary switch is
in the ON position when installing the
batteries, it causes an electrical surge,
which can damage the tubes.
BATTERIESBATTERIES

6262
There are two distinct models of NVG
tubes. Third generation tubes have
increased performance and a buyer tube
life than second generation tubes.
A. True
B. False
QUESTION:QUESTION:

6363
QUESTION:
 NVG’S can operate at temperatures below
freezing.
A. True
B. False

6464
QUESTION:
 The IR illuminator provides light, invisible
to the naked eye, for viewing up to 3 meters
in ____________________.
A. High
B. Low
C.Medium

6565
QUESTION:
 What position must the selector switch
be in when installing or removing the
battery?
A. ON position
B. OFF position
C. IR off

6666
QUESTION:
 Improper adjustment of the _____will
result in eye fatigue.
A. Inter-pupillary (eye span) adjustment.
B. Clamp knobs
C. Head-strap assembly.

6767
QUESTION:
 The sharpest image will be observed only
when the ________________.
A. Objective lens/lenses are focused.
B. Objective lens/lenses and both eyepieces
are properly focused.
C. Eyepieces are properly focused.

6868
QUESTION:
 It is not necessary to focus one eye at a time
with the diopter adjustment rings.
A.True
B. False

6969
QUESTION:
 The monocular tubes on the AN/PVS-5 &
the image intensifier tube on the AN/PVS-7
__________ available ambient light.
A. Amplify
B. Magnify
C. Reduce

7070
DIMINISHING EFFECTSDIMINISHING EFFECTS
• Rain
• Fog
• Snow
• Smoke
• Pollution
• Clouds
• Dust

7171
DEBILITATING EFFECTSDEBILITATING EFFECTS
• Street lights
• Airplane lights
• Automobile lights
• Flares
• Spot lights
• Dash lights
• Matches or lighter
• Blackout drive and marker lights

7272
DEBILITATING EFFECTS
 NVG compatibility is best achieved by eliminating
all interior and exterior light sources. Tape lights
that cannot be controlled to reduce the amount of
light they emit. Instruments and gauges can
normally be read with NVG’s without instrument
lighting. Gauges can degrade the performance of
the NVG’s.

7373
DEBILITATING EFFECTS
 Blackout drive and markers are not needed to
operate a vehicle while using NVG’s, however,
the route should be restricted to other traffic not
also using NVG’S*. Viewing an area lit by
artificial light, such as flares or street lamps will
limit your ability to see objects outside the lighted
area. Operating the goggles while staring at a
bright light source at night will cause damage
to the tubes.

7474
 Driving in an area lit by artificial lights
such as flares, will limit your ability to
see objects
A. Inside the lighted area.
B. Outside the lighted area.
QUESTION:QUESTION:

7575
QUESTION:
Driving with blackout drive lights will
increase distance vision, but decrease near
vision , and may blind oncoming drivers
wearing NVGs.
A. True
B. False

7676
QUESTION:
 NVG compatibility is best achieved by
eliminating all interior and exterior vehicle
lights.
A. True
B. False

7777
QUESTION:
 Operating the goggles while staring at a
bright light source at night will cause
damage to the tubes.
A. True
B. False

7878
QUESTION:
Driving with instrument panel lights on
will not degrade NVG performance.
A. True
B. False

7979
PERCENTAGE OF MOON ILLUMINATION
OVERCAST STARLIGHT CRESCENT MOON HALF MOON FULL MOON
1% 5% 10% 25% 30% 75% 90% 100%
200
150
100
50
0
H
A
Z
A
R
D
D
E
T
E
C
T
I
O
N
I
N
M
E
T
E
R
S
HAZARD RECOGNITION RANGE

8080
300
250
200
150
100
50
0
GROUND SPEED LIMITATIONS
10 20 30 40 50 60
RANGE
IN
METERS
GROUND SPEED
10 SECONDS RESPONSE LINE

8181
OTHER FACTORS TOOTHER FACTORS TO
DETERMINE SPEEDDETERMINE SPEED
• Type of vehicle used for training.
• Weather conditions.
• Mode of driving, such as convoy, off-road, and
• cross-country.
• Terrain.
• Amount of light available.
• Type of mission.
• Experience of soldiers.

8282
 At what speed can you safely drive with
NVG’S if the sky is overcast and only 5%
illumination is available?
A. Approximately 8MPH
B. Approximately 3MPH
C. Approximately 10MPH
QUESTION:QUESTION:

8383
CAUSES OF EMERGENCIESCAUSES OF EMERGENCIES
• Overconfidence.
• Exposure to bright light.
• Vehicle or goggle malfunction.
• Batteries go dead.
• NBC environment.

8484
EXPOSURE TO A BRIGHT LIGHTEXPOSURE TO A BRIGHT LIGHT
 If you are exposed to a bright light source while
operating a vehicle and using NVG’s:
SLOW DOWN; LOOK AWAY FROM THE LIGHT
SOURCE SO THAT THE LIGHT IS JUST OUTSIDE YOUR
FIELD OF VIEW;
PULL OFF TO THE FAR RIGHT-HAND SIDE OF THE
ROAD;
STOP THE VEHICLE;
WARN OTHER TRAFFIC. Warn other traffic
with a tactical flashlight or CHEMLITE.

8585
VEHICLE OR GOGGLEVEHICLE OR GOGGLE
MALFUNCTIONMALFUNCTION
If your vehicle or goggle malfunctions:
SLOW
DOWN; PULL OFF TO THE FAR RIGHT-
HAND SIDE OF THE ROAD; STOP THE
VEHICLE.

8686
BATTERIES GO DEADBATTERIES GO DEAD
Replace batteries when the battery indicator
turns on. DO NOT wait until the goggles shut
down due to weak or dead batteries while
driving.
SLOW DOWN AND PULL OFF TO THE FAR
RIGHT-HAND SIDE OF THE ROAD AND
STOP. Warn other traffic before you attempt
to change the batteries. DO NOT switch
goggles or you will have to refocus the
device to suit your eyesight.

8787
 To minimize the impact of an oncoming
vehicle’s headlights on the NVG, the
operator should______________.
A. Look away from the light source & continue to
drive.
B. Slow down, look away from the light source
and if possible , pull off to the right-hand
side of the road.
C. Slow down & pull off to the right-hand
side of the road.
QUESTION:QUESTION:

8888
NBC ENVIRONMENTNBC ENVIRONMENT
DO NOT OPERATE A VEHICLE WHILE
WEARING NVG’S AND A
PROTECTIVE
MASK UNLESS ABSOLUTELY
NECESSARY.
YOUR FIELD OF VIEW IS REDUCED
TO 20 DEGREES!!!!
(Normal field of views are 200* unaided
and 40* with NVG’S only.)

8989
DRIVER RESPONSIBILITYDRIVER RESPONSIBILITY
• Get plenty of rest.
• Stay fit.
• PMCS.
• Know your route.
• Focus NVG’s for outside of the cab.
• Maintain proper following distance (at least
10
seconds.
• Know emergency procedures.
• Always communicate.

9090
ASSISTANT DRIVERASSISTANT DRIVER
RESPONSIBILITYRESPONSIBILITY
• Stay fit and get plenty of rest.
• PMCS.
• Know the route
• Focus NVG’s for inside and out side of the
cab
“alternating”. NOTE: Spatial disorientation
may be caused if you focus one tube inside
and one tube outside of the cab.
• Know emergency procedures.
• Always communicate.

9191
ACCOUNTABILITY AND SECURITYACCOUNTABILITY AND SECURITY
OF NIGHT VISION GOGGLESOF NIGHT VISION GOGGLES
• Night vision goggles are considered a sensitive
item. They must be physically inventoried by
an E-7 or above on a monthly basis.
• Night vision goggles will be kept in a secure
area such as an arms room or company safe.
• When being used, night vision goggles
will be accounted for by using a
DA Form 2062 or DA Form 3161.

9292
 Operating a vehicle with the goggles worn
the NBC mask will not reduce your field of
vision.
A. True
B. False
QUESTION:QUESTION:

9393
QUESTION:
 If riding in a vehicle as an assistant operator,
focus the NVG for______________.
A. Distance viewing.
B. Close-up viewing for reading instrument
gauges.
C. Both distance and close-up
viewing (alternating).

9494
Driver PreparationDriver Preparation
NVG VGT-93
• Keep physically fit.
• Eat a well-balanced meal.
• Get adequate rest.
• Avoid self-medication.
• Avoid the use of tobacco and alcohol.
• Avoid bright lights after dark adaptation.
• Avoid bright sunlight during the day.

9595
Driving with GogglesDriving with Goggles
NVG VGT-94
• Developed through continuous practice.
• Awareness of NVG CAPABILITIES and LIMITATIONS
is KEY
• EMERGENCY PROCEDURES:
- Effects of oncoming headlights
- Tube failure while driving
- Vehicle breakdown procedures
- Low battery light indicator
 Speed Discipline
 Communication
 Assistant Operator Responsibilities

9696
Driving With The NVGDriving With The NVG
NVG VGT-95
Phase I:
Drive a vehicle on a designated route in DAYLIGHT conditions.
Phase II:
Drive a vehicle on a designated route at night with vehicle headlights
on (without NVGs).
Phase III:
• Perform pre-operational NVG procedures.
• Perform vehicle PMCS (before OP) while wearing NVG.
• Drive a designated route at night with NVGs.
• Identify signs, route markings, ditches, etc.
• Perform post-operational NVG procedures.
• Perform vehicle PMCS (after OP) while wearing NVGs.
SAFETY FIRST !!!

9797
NVG VGT-96
SAFETY FIRST !!!

Principles of Night Vision and NVG Driving

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