Vision Flashcards
What protects the iris and lens?
Cornea
What converts light to nerve muscles for brain interpretation?
Retina
What focuses light onto the retina?
Lens
What is the natural focal distance of the eye?
1-2m
What are the two light receptors?
Rods and cones
What eye receptor needs good light?
Cones
What eye receptors operate in lower light conditions?
Rods
What part of an eye is most susceptible to loss of oxygen (and thus hypoxia)?
Cones
What light receptors provide colour vision?
Cones
How to remember cones provide colour vision?
C for Colour, C for Cones
What light receptors provide peripheral vision?
Rods
How are rods and cones distributed in the eye?
Cones in the centre (fovea) and rods on the outside
What light receptors are useless at night?
Cones
How long do rods take to become fully responsive for night vision?
30-40 minutes
What light receptors are best for motion detection?
Rods
Why are moving objects most likely to be detected in the peripheral vision?
Rods detect motion best and are used for peripheral vision
When eyes move in jerks, what are these jerks called?
Saccades
Why do older people develop long-sightedness?
The lens loses its elasticity and loses the power to focus on close objects
What is perception?
How we interpret what we see in the context of our understanding
How we interpret what we see in the context of our understanding is known as?
Perception
What effect of vision means stationary objects ‘appear’ to move (especially at night)?
Autokinesis
How does rain on the windshield affect vision?
It refracts light and makes the horizon appear lower than it actually is
Refracted light from rain on the windshield has what major impact on flying?
Pilot thinks they are higher than they actually are
Other than sloped runways, when might a pilot think they are higher than they actually are?
When rain is on the windshield
At night, what happens to lit objects in vision?
They appear closer than they actually are
When do lit objects appear closer than they actually are?
At night
Why do lit objects appear closer than they actually are at night?
The brain interprets brighter objects as closer objects
