According to todays Page Six, the reason for Paris Hilton's famously wonky eye is due to a botched eye surgery and the fact that she wears blue-colored contacts is only making it worse:

WHEN Paris Hilton decided to turn her brown eyes blue with tinted contacts, she might have hurt her already suffering eye lids. According to a Beverly Hills source, Hilton stopped by a plastic surgeon’s office with sis ter Nicky earlier this week, seeking to “fix her drooping left eyelid.” Our insider says Paris had hush- hush surgery six years ago to lift her lids. The muscles of her left eye were supposedly damaged as a result, “causing it to droop more than the right” - a look that was once parodied on “South Park.” Hilton, who is filming “The Hottie and the Nottie,” has made things worse by wearing blue- tinted contact lenses over her naturally brown irises. “They have been drying out lately,” dished the tipster. “She is ignor ing doctors’ orders to not wear her tinted contacts.” Paris’ rep Elliot Mintz told Page Six, “To the best of my knowledge, Paris has never had any kind of cosmetic surgery and has not mentioned any medical procedures having to do with her eyes.”

Whatever. Her eye has been droopy since birth. Check out her elementary school photos below. She might have had surgery to try and correct it and that was botched but she has had that wonky eye since the day she was born.