In “Harry Potter and the Prisoner of Azkaban,” the bespectacled boy wizard advised his pal Ron Weasley to get his “inner eye tested.” We’re not sure about Ron, but Hogwarts headmaster Severus Snape spent time in the chair at Eisenbrei Plaza Optical in Canton, OH, as part of a Potter-themed Facebook contest the practice ran to boost social media traffic, timed to mark Harry’s birthday. The winner took away a package of Potter goodies.