This document outlines the causes, categories, diagnostic approach, and management strategies for adult onset strabismus and diplopia. It discusses emergent causes such as pituitary apoplexy and aneurysmal CN III palsy. It categorizes causes as neurological, orbital/muscular, or neuromuscular junction disease. The diagnostic approach involves clinical examination, ancillary testing such as imaging and lab studies. Management options include patching, temporary prisms, or strabismus surgery versus chronic prism use.