optics physics 50 optic instruments 40 geometrical optics 29 mathematics 24 classical mechanics 23 astronomy 19 more ... lasers 19 light 17 electricity and magnetism 13 geometry 13 optoelectronics 13 acoustics 12 perspective 10 architecture 9 artist colours 9 arithmetic 8 light refraction 8 spectroscopy 8 theory of light 8 measuring methods 7 optical materials 7 positional astronomy 7 research 7 lenses 7 atomic physics 6 microscopy 6 spectral analysis 6 engineering 6 thin films 6 less ...