Optics

(op'tiks.) [From Gr. optomai, to see.) The science which treats of the laws of vision and light,whether direct, reflected, or refracted. In a more simple application, O. is the science of direct vision only, while the science of the laws and properties of the rays of light, when considered as reflected, is called catoptrics, and the science of refracted rays dioptrics; but in its general sense, O. comprehends the whole of that of which catoptrics and dioptrics are two parts. For information regarding the different branches of this science, recourse must be had to the different heads. See EYE, LIGHT, MICROSCOPE, REFLECTION, REFRACTION, TELESCOPE, .Optic angle, that which the optic axes of the eyes make with one another, as they tend to meet at some distance before the eyes.- Optic axis, the axis of the eye, or a line going through the middle of the pupil and centre of the eye. Optic nerves. (Anat.) The second pair of nerves from the brain, which perforate the bulb of the eye, and serve for the sense of sight. [s. 665]