noun
: a microscope in which light rays are seen directly by the observer as distinguished from one (as an electron microscope) in which some transformation or system of indirect viewing is used
noun
: a microscope in which light rays are seen directly by the observer as distinguished from one (as an electron microscope) in which some transformation or system of indirect viewing is used
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012