A toothache of his "eye" tooth causes "eye" problems for Martin: he can't see. Tim takes him to see his dentist, although Martin doesn't have typical human teeth. He needs dental expertise and some dental powder without the dentist actually examining him, which is why dentist-phobic Tim takes the place in the dental chair. The remedy causes Martin's eye teeth to go crossed eyed, as does his vision. The only answer is tooth extraction. (thetvdb.com)