05. The Eye and Vision Flashcards by C MC

Anatomy of the Visual System

What 3 elements does the visual system comprise of?

EYES
OPTIC NERVE
VISUAL CORTEX

pg 112

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Anatomy of the Visual System

What does the optic nerve connect the eyes to

VISUAL CORTEX

pg 112

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Anatomy of the Visual System

What is the visual cortex

AREA AT BACK OF BRAIN
Responsible for processing information received by the eyes

pg 112

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Anatomy of the Visual System

The outside eye is covered in a smooth, very tough layer of white tissued called what

SCLERA

pg 114

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Anatomy of the Visual System

The ____ allows light to enter the eye and fall onto the lens

TRANSLUCENT CORNEA

pg 114

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Anatomy of the Visual System

The hole in the iris is known as what

PUPIL

pg 114

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Anatomy of the Visual System

The ___ contracts and expands in response to light levels

IRIS

pg 114

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Anatomy of the Visual System

The cornea helps focus light onto which part of the eye

RETINA

pg 114

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Anatomy of the Visual System

The focusing process, in which the contraction and relaxation of the ciliary muscle takes place, thus changing the focal length of the lens, is known as what

ACCOMMODATION

pg 114

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Anatomy of the Visual System

The back of the eye is densely packed with what 2 things

hint
1. which reacts to light and colour
2. which reacts to stimuli

PHOTORECEPTORS (cones and rods)
NEURONS

pg 114

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Anatomy of the Visual System

What are the 2 types of photoreceptors

RODS - sensitive to light
CONES - colour detection

pg 115

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Anatomy of the Visual System

RODS or CONES are the most sensitive receptor to light

RODS

REMEMBER
Cones = Colour

pg 115

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Anatomy of the Visual System

RODS or CONES are the most sensitive receptor to colour

CONES

REMEMBER
Cones = Colour

pg 115

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Anatomy of the Visual System

What are the 2 fluids that help maintain the spherical shape of the eye

AQUEOUS HUMOUR
VITREOUS HUMOUR

pg 116

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Anatomy of the Visual System

What liquid occupies the space in front of the lens

AQUEOUS HUMOUR

REMEMBER
Advanced; meaning forward = Aqueous
Volume; meaning larger space = Vitreous

pg 116

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Anatomy of the Visual System

What liquid occupies the space behind of the lens

VITREOUS HUMOUR

REMEMBER
Advanced; meaning forward = Aqueous
Volume; meaning larger space = Vitreous

pg 116

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Anatomy of the Visual System

What component of the eye washes the surface with a mildly antibiotic solution

TEAR DUCT

pg 116

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Anatomy of the Visual System

Why is it important for the cornea to be kept moist at all times

HELPS DIFFUSE OXYGEN

pg 116

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Anatomy of the Visual System

What is the purpose of the 2 photoreceptors rods and cones

DETECT LIGHT and COLOUR
Rods - black and white, highly sensitive to light
Cones - colour, less sensitive to light, not used at night

pg 117

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Anatomy of the Visual System

The axons of the cells to which the rods and cones are connected to, exit the eye at what point

OPTIC DISC

pg 117

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Anatomy of the Visual System

The optic disc has no (i) ____, and as a result, cannot detect (ii) ____.
This is therefore known as the (iii)____

PHOTORECEPTORS
LIGHT
BLIND SPOT

pg 117

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Anatomy of the Visual System

CONES or RODS are the principle means of vision during the day

CONES

REMEMBER
Ice cream cones by the beach on a sunny day

pg 117

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Anatomy of the Visual System

CONES or RODS are the principle means of vision during the night

RODS

REMEMBER
Ice cream cones by the beach on a sunny day
Rods are highly sensitive to light, which there is little of in the dark

pg 117

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Anatomy of the Visual System

The central area of the retina, which is densely packed with cones, is known as what

FOVEA

pg 117

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# Anatomy of the Visual System The area immediately surrounding the *fovea* is densely packed with what

RODS and CONES ## FOOTNOTE pg 117

# Anatomy of the Visual System The number of cones *INCREASE or DECREASE* as you move progressively outwards from the fovea

DECREASE ## FOOTNOTE pg 117

# Anatomy of the Visual System Which part of the retina is able to resolve letters and numbers, and why

1. FOVEA 2. DENSELY PACKED WITH RODS AND CONES ## FOOTNOTE pg 118

# Anatomy of the Visual System Which part of the eye is most sensitive to detecting objects at night and why

1. PERIPHERAL VISION 2. Cones DECREASE outwards from the fovea (center of retina), rods are more sensitive to light ## FOOTNOTE pg 118

# Anatomy of the Visual System The entire area of space which can be seen at any one time is known as what

VISUAL FIELD ## FOOTNOTE pg 119

# Anatomy of the Visual System The sudden and jerky movement of the eye is known as what

SACCADE ## FOOTNOTE **THINK** **S**ide-to-side = **S**accade where AC and CA are side by side pg 120

# Anatomy of the Visual System Which part of the visual system is specifically tuned to respond to relative movement

VISUAL CORTEX ## FOOTNOTE pg 120

# Anatomy of the Visual System The process of our eyes smoothly tracking a moving object is known as what sort of movement

PURSUIT MOVEMENT ## FOOTNOTE **THINK** Following is in *pursuit* pg 120

# Anatomy of the Visual System Objects passing through the field of vision are tracked. This allows them to be ____ upon, which allows them to be tracked again. This is an alternating pattern of ____ and ____ movement of the eye

1. FIXATED 2. PURSUIT 3. SACCADE ## FOOTNOTE pg 120

# Anatomy of the Visual System A group of how many muscles make eye movements What part of the eye are the muscles attached to

1. 6 2. SCLERA ## FOOTNOTE pg 121

# Vision The process of taking signals from the eyes an interpreting them in the brain is known as what

VISION ## FOOTNOTE pg 122

# Vision Why is some visual acuity lost in the dark

CONES NOT CONTRIBUTING Cones, which require high levels of flight to function, are not contributing to object detection ## FOOTNOTE pg 123

# Vision What are 2 biological reasons for a loss of visual acutiy

1. AGE 2. DISEASE ## FOOTNOTE pg 123

# Vision What are 5 physiological factors for reducing visual acuity ## FOONOTE **REMEMBER** You are *mash less* **M** **A** **S** **H** **LsSs**

1. MEDICATIONS 2. ALCOHOL 3. SMOKING - excessive CO2 4. SHORT/LONG SIGHTEDNESS 5. HYPOXIA - cabin altitude > 5,000 ft ## FOOTNOTE **REMEMBER** MASShH (MASH) **M**edications **A**lcohol **S**moking **H**ypoxia **L**ong **s**ightedness **S**hort **s**ightedness pg 123

# Vision Visual fields of each eye overlap, which creates what sort of vision. This is necessary for what

1. BINOCULAR / STEREOSCOPIC 2. DEPTH PERCEPTION (short distance) ## FOOTNOTE pg 124

# Vision What range is stereoscopic depth perception effective up to

60 m (200 ft) ## FOOTNOTE pg 124

# Vision Another term for binocular vision is what

STEREOSCOPIC VISION ## FOOTNOTE pg 124

# Vision What are the 4 visual cues used beyond stereoscopic vision to infer depth

1. COLOUR 2. CONTRAST 3. SIZE 4. RATE OF MOVEMENT ## FOOTNOTE 1. COLOUR - Paler objects considered more distance 2. CONTRAST - decreasing contrast seen as increasing distance 3. SIZE - large objects seen as small object inferred as distant 4. RATE OF MOVEMENT - angular displacement far away is reduced. Rapid movement therefore inferred to be closer pg 124

# Vision What sort of vision results in the loss of all depth perception

MONOCULAR (one eyed) ## FOOTNOTE pg 124

# Dark and light adaptation The process of increasing retinal sensitivity to reducing light is known as what

DARK ADAPTATION ## FOOTNOTE pg 125

# Dark and light adaptation It takes 7-9 minutes for *CONES or RODS* to become adapted to dark It takes 30 minutes for *CONES or RODS* to become adapted to dark

1. CONES 2. RODS ## FOOTNOTE **REMEMBER** C before R **C** for **c**ones comes before **R** for **r**ods in the alphabet pg 125

# Dark and light adaptation How long does it take for the eye to adapt from darkness to bright light conditions

10 seconds ## FOOTNOTE pg 126

# Dark and light adaptation Bleaching of the retina from sudden exposure to bright light is known as what

FLASH BLINDNESS ## FOOTNOTE pg 126

# Dark and light adaptation Why is it recommended to turn up the lights in the cockpit at night during a thunderstorm

AVOID FLASH BLINDNESS happens when the eyes are bleached from the sudden flash of lightening ## FOOTNOTE pg 126

# Dark and light adaptation Rods and cones are very sensitive to the effects of what condition that typically could occur at high altitudes

HYPOXIA ## FOOTNOTE pg 126

# Dark and light adaptation What operational maintenance process is a prime culprit to eye damage in the aviation industry over time

ARC WELDING ## FOOTNOTE Repairing the fuselage using welding torches pg 127

# Dark and light adaptation At what end of the spectrum does the highest level of light energy occur (what colour). What level is the highest risk (light range) Where do these light energies typically occur (altitude)

1. BLUE 2. ULTRAVIOLET 3. HIGH ALTITUDES ## FOOTNOTE pg 127

# Dark and light adaptation When selecting sunglasses for the cockpit, what 4 qualities should you try to ensure they meet 1. ____ : brand 2. ____ : made from 3. ____ : frames 4. ____ : regulation

1. HIGH QUALITY 2. POLYCARBONATE MATERIAL 3. THIN / NO RIMS 4. CONFORMS with EN 1836:1997 ## FOOTNOTE pg 128

# Dark and light adaptation What 2 types of sunglasses are not permitted in the flight cockpit

1. PHOTOCHROMIC 2. POLARISED ## FOOTNOTE pg 128

# Physiological limitations Why is it important to frequently change your focus of attention when looking out of the cockpit window

BLIND SPOT avoid potential threat coinciding with the blind spot ## FOOTNOTE pg 129

# Physiological limitations When the eye has no objects to attract its attention, this causes issues with the ability to focus on distant objects. This is known as what

EMPTY FIELD MYOPIA ## FOOTNOTE pg 131

# Physiological limitations When suffering from *empty field myopia*, the eyes will result to default focus, which is a range of approximately how far

1 - 2 METRES ## FOOTNOTE pg 131

# Physiological limitations What are 2 key issues related to focusing and vision in the dark

1. PUPILS DILATED 2. ONLY RODS USED - few located near fovea ## FOOTNOTE Dilated pupils removes the beneficial effect a constricted pupil brings for focusing. There are few rods located near the fovea. pg 132

# Physiological limitations People with what sort of eyesight have issues focusing in the dark

POOR EYESIGHT ## FOOTNOTE pg 132

# Physiological limitations At night, it is sometimes necessary to look at objects using peripheral vision, meaning you are looking at the object ____. Why is this required

1. OFF-CENTRE 2. ONLY RODS USED ## FOOTNOTE Few rods in the fovea. Since only rods are used at night, and these are used more specifically in the peripheral vision, it is better to look off-centre to help with object detection. pg 132

# Physiological limitations When scanning the sky, how much should each stop overlap with the last search field

10° ## FOOTNOTE pg 133

# Defective vision Cones detect colour vision. This is known as what

PHOTOPIC VISION ## FOOTNOTE pg 134

# Defective vision Rods detect various shades of light and dark. This is known as what

SCOTOPIC VISION ## FOOTNOTE pg 134

# Defective vision The most common type of eye defect is what

REFRACTIVE ERROR ## FOOTNOTE pg 135

# Defective vision *Myopia* is what sort of eye defect

SHORT SIGHTEDNESS ## FOOTNOTE pg 135

# Defective vision What is short sigtedness known as

MYOPIA ## FOOTNOTE pg 135

# Defective vision *Hyperopia (hypermetropia)* is what sort of eye defect

LONG SIGHTEDNESS ## FOOTNOTE pg 135

# Defective vision Long sightedness is known as

HYPEROPIA ## FOOTNOTE pg 135

# Defective vision What sort of lens will be used to correct vision for someone suffering from *myopia*

CONCAVE ## FOOTNOTE Short sightedness, concave (inwards sloping) lens pg 135

# Defective vision What sort of lens will be used to correct vision for someone suffering from *hyperopia*

CONVEX ## FOOTNOTE Long sightedness, convex (outwards bowing) lens pg 135

# Defective vision Long sightedness / hyperopia is the inability to focus on what Short sightedness / myopia is the inability to focus on what

1. NEAR OBJECTS 2. FAR AWAY OBJECTS ## FOOTNOTE pg 135

# Defective vision What is *astigmatism*

SLIGHT IMPERFECTIONS in CORNEA or LENS ## FOOTNOTE pg 137

# Defective vision Slight imperfections in the *cornea or lens* that causes slight variations in optical power between areas of the cornea is known as what

ASTIGMATISM ## FOOTNOTE pg 137

# Defective vision What are the conditions that must be met by a pilot in order to retain their pilot licence/medical if using corrective lenses; 1. Not worse than ____/____ vision in *either eye* 2. Not worse than ____/____ vision in *both eyes* 3. Read small print up to ____cm (same as _which_ line in snellen chart)

1. 6/9 2. 6/6 3. 30cm 4. Next to bottom ## FOOTNOTE pg 138

# Defective vision Wherever corrective glasses are used, what must a pilot carry at all times when exercising their pilots licence

SPARE PAIR ## FOOTNOTE pg 138

# Defective vision When using corrective glasses, *bifocal* lenses *ARE or ARE NOT* permitted

ARE PERMITTED ## FOOTNOTE pg 138

# Defective vision When using corrective contact lenses, *bifocal* lenses *ARE or ARE NOT* permitted

ARE NOT PERMITTED ## FOOTNOTE pg 138

# Defective vision What is *presbyopia*

LONG SIGHTEDNESS reduction in the elasticity of the lens ## FOOTNOTE pg 139

# Defective vision Long sightedness caused by a reduction in the elasticity of the lens, typically age related is known as what

PRESBYOPIA ## FOOTNOTE pg 139

# Defective vision What is cataracts

CLOUDING OF LENSES OF EYES ## FOOTNOTE pg 140

# Defective vision A clouding of the lenses of the eyes is known as what condition

CATARACTS ## FOOTNOTE pg 140

# Defective vision Cataracts is a progressive disease that results in increasingly what sort of lenses

OPAQUE ## FOOTNOTE pg 140

# Defective vision Internal (intraocular) pressure of the eye increases. This condition is know as what

GLAUCOMA ## FOOTNOTE pg 141

# Defective vision What is *glaucoma*

INTERNAL (INTRAOCULAR) PRESSURE OF THE EYE INCREASES ## FOOTNOTE pg 141

# Defective vision What is an early symptom of *glaucoma*

LOSS OF VISUAL ACUITY ## FOOTNOTE pg 141

05. The Eye and Vision Flashcards

(84 cards)