These optics are also of special crystal and fit over the eyes of the wearer.

They give vision 100 times greater than normal at distances of 1' or more,
i.e. the wearer can see at 2,000' what a person could normally see at 20'.

Wearing only 1 of the cusps will cause the character to become dizzy, and in effect stunned, for 1 round.
Thereafter, 1 eye must always be covered to avoid this vertigo.

Note: Mixing eye types is certain to cause immediate insanity for 2-8 (2d4) turns.