Here is a list of the most commonly used terms for night vision devices. Please note that this is not a comprehensive list and these terms may vary from person to person (depending on who you ask).
This is an automatic feature built into modern NVDs whereas they automatically reduce voltage passed onto the microchannel - when changing from a dark environment onto a bright one - to protect the tube and keep the image at a constant brightness level.
In short, black spots are dirt which remains between the lenses. They are perfectly normal.
Cycles per Milliradian are used to measure a system's resolution.
A diopter is used to accommodate each person's eyesight. The military uses a diopter range of +2 to -6 (usually).
Unit of illuminance which equals one lumen per square foot.
Unit of brightness which equals one footcandle at a distance of one foot.
Number of photons perceived by the human sight in one second.
A monocular is a singlechannel optical device.