GB/T 1224-1999 Unify the terms and symbols of geometrical optics. This standard systematically sorts out a large number of geometrical optics terms, accurately defines the concepts of optical axis, focus, focal length, etc., and avoids ambiguity in expression. At the same time, it standardizes related symbols, such as the direction of ray of light propagation, the representation of refraction angle of reflection, etc. By unifying terms and symbols, it promotes the exchange and dissemination of knowledge in the field of Optical inspection, and facilitates scientific researchers and engineers to communicate accurately in scenarios such as paper writing, technical discussions, product design and teaching. It lays the foundation for the theoretical research of geometrical optics, the design and manufacture of opticalin strument, and promotes the standardized development of the Optical inspection industry.