Spectacles definition clarifies corrective and protective eyewear scope, including sunglasses and safety frames. Spectacles are optical devices of lenses set in a frame to assist or protect vision, covering corrective and protective functions. The term includes eyeglasses, bifocals, prismatic and decentered lenses, tinted or sunglass lenses, and safety or industrial spectacles designed to guard against foreign bodies, ultraviolet or infrared radiation. Specialized forms-periscopic, stenopeic, mica, pulpit and wire-frame spectacles-are identified as structural or functional variants relevant to classification.