The moment when you think you see someone attractive out of the corner of your eye (the peripherals), and momentarily find them attractive before getting a better glance and realizing that they are a sub-par, or unfortunate looking individual
Inner monologue... "Ouuu damn, that guy is really hot!...oh.. oh. No wait, statement retracted, he’s just the Mexican janitor. Thought he was hot from the corner of my eye. He’s peripheral hot."