NVD Flashcards
What component of the eye adjusts pupil size to allow light into the eye?
Iris
______ cells are less effective as light levels decrease.
Cone
Which type of vision is characterized by lack of color perception and requires off-center viewing?
Scotopic
How long does it take to recover dark adaptation due to exposure to a bright light?
5-45 min
When is the lens flexible?
When young
Where does the optic nerve enter the retina?
Optic Disc
What is the transition zone between photopic, and scotopic vision called?
Mesopic Vision
Dark adaptation normally takes how long?
30 - 45 min
How large is the night-blind spot?
5 - 10 deg
Why is the circular overlap in a scan pattern 10 degrees?
To ensure coverage of an area greater than the night-blind spot
What information does motion parallax provide aviators?
Aircraft speed and direction of movement
What is visual acuity?
The ability to resolve detail in an object
Crewmembers should overlap the previous field of view by how many degrees to ensure they compensate for the night-blind spot?
10 degrees
What is distance Estimation?
It tells how far away an object is from the viewer
What surface is the most difficult to hover over?
Water
What is the primary function of the iris?
Adjusts pupil size to allow light into the eye