optics physics 42 optic instruments 35 geometrical optics 28 classical mechanics 21 mathematics 20 astronomy 17 more ... lasers 13 optoelectronics 13 light 12 acoustics 11 electricity and magnetism 11 arithmetic 8 geometry 8 light refraction 8 theory of light 8 measuring methods 7 optical materials 7 architecture 6 positional astronomy 6 wave optics 6 research 6 artist colours 5 electromagnetic waves in dielectrics 5 mathematical physics 5 material engineering 5 microscopy 5 measurement 5 optical imaging 5 perspective 5 less ...