Arcane eye

Arcane eye, also known as wizard eye, was an arcane divination spell that allowed its caster to spy on things from a distance.

Effects
The spell would create an invisible floating "eye",  about one inch (two and a half centimeters) in diameter, which would provide the caster with visual information. The eye could see up to ten feet (three meters) with infravision and with a normal visual range after that and could move between 30 feet (ten meters) to 300 feet (100 meters) per minute. It moved more slowly if the caster was looking more than only straight ahead. The eye could be created anywhere within sight but could move to any distance from the caster.

Solid barriers blocked the eye, but it could fit through holes that were not smaller than its diameter. It could not pass through portals or other means of entering other planes.

Although the eye could not be used unless the caster was actively concentrating, a break in concentration merely disabled the eye and did not end the spell, and concentration could be resumed later. The spell was effective even if the caster was blind or in an area of magical darkness, as long as the eye itself was not.

Components
The spell took a full ten minutes to cast and required verbal, somatic, and material components. The material component was a bit of bat fur.

History
This spell was the first of many developed by Netherese arcanist Trebbe in. It was then called Trebbe's eye.