The Eyes of the Overworld

The Eyes of the Overworld is the monk quest artifact. It is neutral for wishing purposes.

Its base item type is a pair of lenses, so wearing it lets you read spellbooks in two-thirds the time (and with a small intelligence bonus), and you can also search more successfully.

While wearing the Eyes you are granted astral vision: the squares around you are illuminated as would be lit by a lamp. The difference is astral vision penetrates walls, doors, solid rock, and any other obstruction. This is highly useful in trying to find secret doors or trying to navigate Gehennom without magic mapping. While wearing the Eyes, neither blindness nor the Archon's stunning gaze has any effect.

While carried, the Eyes provide magic resistance.

Invoking the Eyes provides enlightenment. You can use this as a semi-reliable method to identify rings and amulets (the only problem is when you try to identify a ring that provides an intrinsic you already have, such as stealth).