The "specially designed contact lenses" thing in cards depends on pre-marked cards, either a man on the inside doing it before the game or surreptiously marking

The "specially designed contact lenses" thing in cards depends on pre-marked cards, either a man on the inside doing it before the game or surreptiously marking them during play (some ink on your hand for example that you can sneak on to cards as you see them in play). That or the glasses can just feed you information gathered elsewhere, like from someone with a view of the cards. They're not x-ray glasses and won't help you with scratch cards. Besides, someone working with a store or bribing a cashier would make way more sense than goofy theatrics about auras.