Ring of the tireless watcher

This magical ring makes the wearer immune to magical sleep. Furthermore, while the wearer must still rest as long as normal, he can sleep standing or sitting upright and with his eyes wide open. He may make Spot checks as normal and takes no penalty on Listen checks, and can rouse from sleep instantly and without penalty should he see or hear something to cause him alarm. While resting in this way, the wearer is still unable to move and can only see things in one direction. Additionally, the wearer still counts as having been interrupted if it rouses itself for the purposes of preparing spells.