night vision orientation

NIGHT VISION NIGHT VISION ORIENTATIONORIENTATION

TERMINAL LEARNING OBJECTIVE

Action:Action: Compensate for Visual Compensate for Visual limitations.limitations.

Condtions: While performing as an Condtions: While performing as an aircrew member.aircrew member.

Standard: In accordance with FM 1-Standard: In accordance with FM 1-301,FM 8-2, and TC 1-204.301,FM 8-2, and TC 1-204.

Depth perceptionDepth perception Visual acuityVisual acuity Blind spotBlind spot Night adaptationNight adaptation Color visionColor vision

ENABLING LEARNINGENABLING LEARNINGOBJECTIVEOBJECTIVE

Identify the limitations of night visionIdentify the limitations of night vision

DEPTH PERCEPTIONDEPTH PERCEPTION

VISUAL ACUITY

BLIND SPOT

NIGHT ADAPTATION 30 to 45 min. for complete adaptation.30 to 45 min. for complete adaptation.

Can take up to 3 to 4 hr. if exposed to Can take up to 3 to 4 hr. if exposed to the glare of snow, water, or sun. the glare of snow, water, or sun.

COLORS VISION

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CUES TO DEPTH PERCEPTION

Binocular cues

Monocular cues

BINOCULAR CUES Valuable only when object is close.Valuable only when object is close. Each eye has a slightly different view.Each eye has a slightly different view.

MONOCULAR CUES Object seen as one picture.Object seen as one picture. Are derived from experienceAre derived from experience

GEOMETRIC PERSPECTIVE Linear perceptive.Linear perceptive. Apparent foresighting.Apparent foresighting. Vertical position in the field.Vertical position in the field.

LINEAR PERSPECTIVE

Parallel lines tend to converge.Parallel lines tend to converge.

APPARENT FORESHORTENING

The shape of object appears ellipticalThe shape of object appears elliptical

VERTICAL POSITION IN THE FIELD

Objects appear to be higher on the Objects appear to be higher on the horizon.horizon.

RETINAL IMAGE SIZE Known size of objects.Known size of objects. Increasing of decreasing size of objects.Increasing of decreasing size of objects. Terrestrial association.Terrestrial association. Overlapping contours.Overlapping contours.

KNOWN SIZE OF AN OBJECT

INCREASING OR DECREASING SIZE OF AND OBJECT

Increase in sizeIncrease in size

Decrease in Decrease in sizesize

TERRESTRIAL ASSOCIATION ASSOCIATION

OVERLAPPING CONTOURS

AERIAL PERSPECTIVE Fading colors or shades.Fading colors or shades. Loss of detail of texture.Loss of detail of texture. Position of light source.Position of light source.

FADING COLORS AND SHADES

Objects viewed through haze, fog and Objects viewed through haze, fog and smoke.smoke.

Transmission of light.Transmission of light.

LOSS OF DETAIL OR TEXTURE

POSITION OF LIGHT POSITION OF LIGHT SOURCE AND DIRECTION SOURCE AND DIRECTION

OF SHADOWOF SHADOW

Direction of the shadowDirection of the shadow

MOTION PARALLAX Very important cue.Very important cue. Relative motion.Relative motion. Depends on the distance of the object.Depends on the distance of the object.

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VISUAL ILLUSIONSVISUAL ILLUSIONS

GENERAL INFORMATIONGENERAL INFORMATION

Decrease in visual information.Decrease in visual information. Spatial Disorientation.Spatial Disorientation. The most reliable senses.The most reliable senses. Misinterpretation of what is seen.Misinterpretation of what is seen.

RELATIVE MOTION RELATIVE MOTION ILLUSIONILLUSION

Motion between you and a moving Motion between you and a moving object.object.

Confusing as to who is moving.Confusing as to who is moving.

GROUND LIGHTS GROUND LIGHTS MISINTERPRETATIONMISINTERPRETATION

Misinterpretation of lightsMisinterpretation of lights.

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FALSE VERTICAL ILLUSIONFALSE VERTICAL ILLUSION

Misinterpretation of the horizonMisinterpretation of the horizon

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DEPTH PERCEPTION DEPTH PERCEPTION ILLUSIONILLUSION

Flying over sand, snow, or water.Flying over sand, snow, or water. Flying through haze, smoke, or fog.Flying through haze, smoke, or fog.

STRUCTURAL ILLUSIONSTRUCTURAL ILLUSION

Curved glass, heat waves, rain, snow, Curved glass, heat waves, rain, snow, sleet, or other disturbance.sleet, or other disturbance.

Disturbance/distortion.Disturbance/distortion.

AUTOKINETIC ILLUSIONAUTOKINETIC ILLUSION

Lack of visual references.Lack of visual references. Off center vision and scanning pattern.Off center vision and scanning pattern.

SIZE DISTANCE

False perception of distance from an object False perception of distance from an object on the ground or in the air.on the ground or in the air.

Misinterprets an unfamiliar object’s size to be Misinterprets an unfamiliar object’s size to be the same as an object they are normally the same as an object they are normally accustomed to viewing.accustomed to viewing.

FLICKER VERTIGOFLICKER VERTIGO

Light flickers at a rate of 4 to 20 cycles Light flickers at a rate of 4 to 20 cycles per second.per second.

May cause nausea, vomiting May cause nausea, vomiting convulsions and unconsciousness.convulsions and unconsciousness.

FASCINATION/FIXATION Pilot intent on hitting target.Pilot intent on hitting target. Pilot forgets to fly aircraft.Pilot forgets to fly aircraft. Fly into target or ground.Fly into target or ground.

REVERSIBLE PERSPECTIVE REVERSIBLE PERSPECTIVE ILLUSIONILLUSION

Happens at night.Happens at night. An aircraft flying parallel to yours.An aircraft flying parallel to yours. Corrective actions.Corrective actions. Observe the aircraft lights.Observe the aircraft lights.

ALTERED PLANES OF ALTERED PLANES OF REFERENCESREFERENCES

Approaching a line of clouds or Approaching a line of clouds or mountains.mountains.

Climb in altitude.Climb in altitude. Tend to tilt away from the clouds.Tend to tilt away from the clouds.

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NERVE AGENTSNERVE AGENTS

Effects on night vision.Effects on night vision. Miosis (pupils will not dilate in low Miosis (pupils will not dilate in low

ambient light).ambient light). Minimal to severe symptoms.Minimal to severe symptoms. Recovery may take up to 20 days.Recovery may take up to 20 days. Insidious onset.Insidious onset.

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FLIGHT HAZARDSFLIGHT HAZARDS

Solar glareSolar glare Bird strikeBird strike LaserLaser

SOLAR GLARESOLAR GLARE

BIRD STRIKEBIRD STRIKE

LASERSLASERS

Type of laser. The energy output. Exposure time. Distance from the laser.

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LASERSLASERS

LASERS - light amplification by a LASERS - light amplification by a stimulated emission of radiation.stimulated emission of radiation.

Very narrow beam of light.Very narrow beam of light. Progressively wider with distance.Progressively wider with distance. May cause severe injuries, burning of May cause severe injuries, burning of

the eyes.the eyes.

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MILITARY LASERSMILITARY LASERS

At 1 kilometer, the beam is 1 meter in At 1 kilometer, the beam is 1 meter in diameter. At 2 kilometers the beam is diameter. At 2 kilometers the beam is 2 meters in diameter.2 meters in diameter.

Can irradiate the whole body.Can irradiate the whole body. Can burn clothing.Can burn clothing. Most are not powerful enough to burn.Most are not powerful enough to burn.

THE EYETHE EYE

The eye is very sensitive to light.The eye is very sensitive to light. Concentration of energy focused on the Concentration of energy focused on the

back of the eye can be up to a 100,000 back of the eye can be up to a 100,000 greater than the energy entering the eye.greater than the energy entering the eye.

Energy being absorbed by various Energy being absorbed by various anatomical structures.anatomical structures.

Factors depends on the type of laser, Factors depends on the type of laser, distance, and energy. distance, and energy.

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PROTECTION AGAINST PROTECTION AGAINST LASER INJURYLASER INJURY

Passive measures.Passive measures. Active measures.Active measures.

PASSIVE MEASURESPASSIVE MEASURES

Take cover Protective gear

Protective Goggles B-LPSNVD

Squinting

ACTIVE MEASURESACTIVE MEASURES

Countermeasures (SOP) Maneuvers

Evasive action Scanning Hardened optical systems

Built-in clip on filter Battlefield smoke screens

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BREAKBREAK

SUMMARY

ANATOMY AND PHYSIOLOGY OF THE HUMAN EYE

Retina

Cornea

Iris

Lens

PupilCones

Rods

IDENTIFY THE COMMON VISUAL DEFICIENCIES

Myopia- nearsightedness Hyperopia- farsightedness Presbyopia Astigmatism

ASTIGMATISM

RADICAL KERATOTOMY Creates spoke-like incisions on the cornea. Permanent disqualification for aviators.

VISUAL DEFICIENCIES

Hyperopia (farsightedness)

Myopia (nearsightedness)

PRESBYOPIA As we get older, the

lens loses the elasticity causing an inability to focus on near objects.

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TYPES OF VISION Photopic vision Mesopic vision Scotopic vision

Photopic Photopic visionvision

PHOTOPIC VISION

Day light or bright light Central vision Color sense and sharp Better visual acuity

MESOPIC VISION Dawn and dusk Parafoveal regions

(rods and cones) Decrease visual

acuity

SCOTOPIC VISION

Night vision Peripheral vision (rods only) Acuity degraded 20/200 color blind Off center viewing to compensate blind

spot

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FACTORS AFFECTING DARK ADAPTATION

Photo sensitivity of the eye

Cones- contains chemical

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PROBLEM WITH RED LIGHTNING

No longer use Blue / green lights Focus behind

retina, causing fatigue

Seen at great distance

Creates glare Bleaches color in

map

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PROTECT NIGHT VISION Sunglasses Adjust cockpit light lowest readable

level Turn off exterior light Close on eye Supplemental oxygen

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PROPER VIEWING TECHNIQUE

Scanning Off-center viewing

STOP-TURN-STOP-TURN

SCANNING

OFF-CENTER VIEWING

View object by looking 10 degree above, below, or to either side.

SELF-IMPOSED STRESSES Drugs Exhaustion Alcohol Tobacco Hypoglycemia