NVG Flashcards
1
Q
A
2
Q
What adjusts pupil size to allow light into the eye?
A
Iris
3
Q
Cone cells
A
- day/high intensity light (>50% illumination)
- identifies Colors
- high visual acuity
4
Q
Rod cells
A
- low light
- identifies outlines and motion
- vision in peripheral regions
- no colors, poor resolution
- produce rhodopsin
5
Q
Night blind spot
A
- fovea centralis
- only cones
- 5-10deg wide
- provides most visual information
6
Q
Day blind spot
A
- optic disk
- where the optic nerve enters the eye
- compensated by binocular vision
7
Q
Types of vision
A
Photopic: Daylight, artificial light; central vision
Mesopic: Twilight, moonlight, NVG; most dangerous
Scotopic: Partial moon, stars; off-center vision
8
Q
Rhodopsin
A
- 30-45min to buildup
- bleached out by bright light
9
Q
Visual acuity
Best NVG vs worst NVG vs best unaided
A
20/25
20/70
20/200
10
Q
Stop-turn scanning technique
A
- Z-pattern, stop between turns
- 10deg overlap
11
Q
Binocular cues
A
- convergence
- stereopsis
12
Q
Monocular cues
A
- geometric perspective
- retinal image size
- aerial perspective
- motion parallax
13
Q
ANVIS Parts
A
Objective lens
- minus blue filter
Eyepiece lens
-
PAS
- grab ANVIS only here
Electrical contacts
- clean with pencil eraser
14
Q
Operational defects
A
Shading
Emission points
Edge glow
Flashing/Flickering/Intermittent Operation
15
Q
A
16
Q
A
17
Q
A
