Four Eyes

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

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. This can be achieved by taking perception 7 at creation, or perception 6 with Intense Training added later to boost it to 7.
 * Wearing glasses with this trait will actually raise perception by +2 as seen in the pip-boy display, thereby nullifying the -1 in terms of accuracy benefits, compass benefits and skill benefits. Perception 7 at creation with this perk (glasses equipped), Intense Training +1 and a +1 perception hat will total 10 perception. If charisma is used as a dump skill it is possible to have x2 SPECIAL stats at 10 by lvl 2, if one of them is perception. Nerd Rage! can further benefit this trait on lower difficulties, allowing a temporary 10 strength as well when health is below 20%.

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.