Visual Deficiencies, Illusions and Spatial D Flashcards
Presbyopia
Normal aging process where the lens on the eye hardens and causes blurred vision for up-close images.
Cataracts during Presbyopia
Clouding of the eye. May occur causing glares to appear with object.
Hyperopia
AKA Farsightedness; where the point of focus is behind the retinal wall. Images up close are blurry
Myopia
AKA Nearsigthedness; point of focus is in front of the retinal wall. Images far away are blurry.
Night Myopia
Slightly nearsighted people will have blurred vision at night with blue/green light. Sharpness of the image decreases as the pupil size increases.
Astigmatism
Unequal curve of the cornea that results in an inability to focus on different place (vertical/horizontal) simultaneously
What is the cause of middle ear discomfort when ascending?
Ear drum bulges out
What is the cause of middle ear discomfort when descending?
Ear drum pushes in. Fast Decent could rupture the ear drum.
In the event you experience a ruptured ear drum due to a fast descent in the aircraft what do you do?
Ascend until pressurized, then slowly descend.
Potential ruptured ear drums can occur when descending how far?
Between 15,000-5,000 ft descents
Spatial Disorientation: Proprioceptive Illusions
Rarely Occur alone
Closely associated with with vestibular illusions and to a lesser degree visual illusions.
Inputs to the brain may lead to false perceptions of true vertical
In a proper turn and without visual references the body senses being pushed into seat and feel as though it was climbing.
Recovery from turn has opposite affect on the body.
When dealing with Spatial Disorientation, what are the two versions of Vesitbular illusions?
Somatogyral
Somatogravic
What are the Somatogyral Vesitbular Illusions?
Leans
Graveyard Spin
Coriolis
What are the Somatogravic Vesitbular Illusions?
Oculogravic
OculoAgravic
Elevator
Describe what the Leans are?
A Somatogyral Vestibular illusion that most commonly occurs when in a slow roll which goes undetected until there is a quick fix in the turn.
Describe Graveyard Spin.
A somatogyral Vestibular Illusion that most commonly occurs in fixed wing aircraft, equillibrium after longturn
Describe Coriolis
A somatogyral Vestibular illusion where there is fluid movement in all three canals of the ear. It is the most dangerous and is gives pilots overwhelming spatial-D
Describe Oculogravic Illusion
A somatogravic vesitbular illusion. occurs when pilot is moving along a linear path and makes a rapid acceleration/deceleration which causes a feeling of nose high or low.
Describe OculoAgravic Illusion
A somatogravic vesitbular illusion. When aircraft is in a downward movement the pilot’s eyes track up and sense a nose low
Describe the elevator illusion
A somatogravic vestibular illusion. When the aircraft is in a upward acceleration the pilot’s eyes track down and sense a rise in the nose.
How can you prevent Spatial-D?
TANN
Trust instruments
Avoid HASHF
Never fly w/o visual references
Never fly VMC and IMC Simultaneously
How do you treat Spatial-D in the aircraft?
Dr. T
- Delay intuitive reaction IOT check references and Instruments
- Refer to instruments. Conduct a good cross-check
- Transfer Controls
In treating Spatial D, we should avoid HASHF. What does HASHF stand for?
Hypoxia Anxiety Smoking Hypoglycemia Fatigue
Definition of Spatial-D
Inability to determine position, attitude, and motion relative to earth’s surface. When it occurs pilots are unable to see, interpret, believe, or prove information from instruments. They rely on false information from senses.
What are the types of Spatial-D?
Type 1: Unrecognized
Type 2: Recognized
Type 3: Uncapacitating
Describe Unrecognized Spatial-D
Most dangerous. Pilot doesn’t think that there are any problems.
Describe Recognized Spatial-D
Pilot knows that there is a problem, but does not realize it is Spatial-D
Describe Incapacitating Spatial-D
The disorientation is so overwhelming the pilot cannot function.
