Four Eyes

 is a Trait which only appears in Fallout: New Vegas.

Special Note

 * Glasses in New Vegas do not provide Perception +1 as they did in Fallout 3, this perk effectively gives them this ability.

Effects

 * Taking this trait effectively lowers your base Perception by 1 point, when attempting to qualify for perks. This means the player must have a base perception of 7 to qualify for all perception based perks (except Infiltrator which requires 8 instead of the usual 7 due to the -1). This can be achieved by taking perception 7 at creation, or perception 6 with Intense Training added later to boost it to 7.
 * This perk functions by removing 1 point from the PER stat that you set at creation (for example, if you raise your PER to 6 at creation, this perk will reset it to 5). The perk will then raise your PER by 2 points whenever you are wearing glasses.

Behind the scenes
This trait's name could be a reference to the film Six-String Samurai, which is about a spectacled man named Buddy (referred to as "Four Eyes" by many of the characters) traveling through a post-apocalyptic wasteland outside of 'Lost' Vegas.