Abstract: A historical development of optics in the 20th century is briefly described. The great contribution of optics to the human society lies in that the two most important discoveries, viz. the special and general relativity as well as the quantum mechanics, were both related to light and optics in the early days of the 20th century. The research and development in optics, especially the invention of laser, fiber communication and optical storage,have promoted the generation of the information society. In the 20th century, traditional optics was striding forward to the modern optics, and photonics and its technology forced open its doorway. It could be expected that the photonic technology will become another principal mainstay in the information society of the 21th century. The practice of science and technology showed that the historical development of optics has demonstrated a part of creative thinking of the human society. With every step forward in recognizing and utilizing photon and light, the human society will make further a big stride forward. Optics--A successful yesterday, a prospective today and a brilliant tomorrow.