appeared spectacle making centres netherlands ref name lzzginzib c page ref first treatise optics johannes kepler ''ad vitellionem paralipomena quibus astronomiae pars optica traditur'' early th century johannes kepler expanded geometric optics writings covering lenses reflection flat curved mirrors principles pinhole cameras inverse square law governing intensity light optical explanations astronomical phenomena lunar solar eclipses astronomical parallax also able correctly deduce role retina actual organ
Natural science Physics Optics