Eyes And Vision Flashcards
The eye sends visual signals to what via the optic nerve?
Visual cortex.
Blank – quick simultaneous
movement of both eyes between
two or more phases of fixation in
the same direction.
Saccade.
What do ciliary muscles move?
The eye.
What focuses 80% of light in the eye?
Cornea.
What opens and closes the pupil in the eye?
The iris.
What is the vitreous humour in the eye?
Jelly substance in the eye.
What is the back of the retina called and where the light is focussed.
The fovea.
What is responsible for your blind spot?
The optic disc.
What is the scalera in the eye?
The white part of your eye.
Whats between the scalera and retina within the eye?
Uvea.
Where are rods and cones located within the eye?
The retina.
What happens to the accommodation of the eye when the ciliary muscles contract.
Becomes thicker and fatter.
What contains rhopsin within the eye?
Rods.
Where are cones located on the retina?
The centre.
How long does it take for light adaptation in the eye?
10 seconds.
How long does it take for rhodopsin to form in a cone compared to a rod?
7minutes in a cone. 30 minutes in rods.
What should you do before a night flight?
Be in a dimmed room.
Night vision is affected above what altitude?
5000ft.
20 cigarettes a pay / or 1 pack will decrease your night vision by what precent?
20%
What is stereoscopic vision also known as?
Binocula.
Binocular vision is effective up to what distance?
200ft.
Non stereoscopic vision means you struggle with blank perception.
Depth perception.
Myopia is short sighted or long sighted?
Short sighted.
What type of lens is used for mytopia?
Diverging.
What type of lens is used for a hyperopic eye?
Converging.
What is astigmatism of the eye?
Misshapen cornea.
What does presbyopia mean in regards to the eye?
Long sightedness due to age.
A cataract is a medical condition when the lens blanks.
Clouding of the eye
What happens the the eye with glaucoma?
Increase in pressure.
What causes a glaucoma?
Blocked drainage canal.
When would you wear your sunglasses at night?
During lightening.
What type of lens should not be used on sunglasses?
Polarised.
What tinted colour glasses should your sunglasses be?
Yellow.
Why can cockpits cause contact lens issues?
Low humidity.
What must you carry if you wear contact lenses?
Glasses.
Can you wear photo sensitive glasses?
No.
Can you wear varifocal glasses?
No.
Can you wear bifocal glasses?
Yes.
Can you wear halfmoon/lookover glasses?
Yes.
Generally, the time required for dark adaptation is?
30 minutes.
Generally, the time required for light adaptation is..
10 seconds.
What are the techniques that will help pilots prevent empty field myopia?
- Scan the sky for other aircraft using peripheral vision to detect movement.
- When possible, avoid flying at Iow level above featureless terrain or large bodies of water.
- Look straight ahead, allowing the eye to naturally focus on the horizon.
- When possible, stimulate the eyes by frequently focusing on distant objects.
124
Name the most important parts of the eye in the order they are met by the light entering the eye, until it reaches the visual cortex. Lens, iris and pupil, cornea, retina.
Cornea, iris and pupil, lens, retina.
A student pilot is seated in a rotating chamber without any outside visual reference. He/she is told to move his/her head up and down slowly. Soon he/she starts to feel dizzy and nausea sets in. What is the reason for this?
Coriolis effect.
In heavy snow, the pilot will think he is traveling at a higher/lower groundspeed,
Higher.
From a dark to light environment, how long does it take for rods to adapt?
10seconds
