Cryptochromatic spectacles

The cryptochromatic spectacles are a pair of special tortiseshell glasses [sic] added to Fallout 3 in the Point Lookout add-on.

Gameplay
They provide a Damage Resistance of 1 and can be repaired with glasses, as well as Doctor Li's glasses and Three Dog's glasses.

Location
The cryptochromatic spectacles are found in the toilet tank in the Homestead Motel's room 1D.

Related quests
The spectacles are used to see hidden color rings during the quest The Velvet Curtain and access the Chinese bunker.

Behind the scenes
The cryptochromatic spectacles are a reference to the 2004 movie National Treasure since the spectacles found in the movie are also cryptochromatic, allowing the wearer to see hidden messages.