1  INTRODUCTION
In 1637 Descartes gave the corpuscular model of light and derived Snell’s
law It explained the laws of reflection and refraction of light at an interface The corpuscular model predicted that if the ray of light (on refraction)
bends towards the normal then the speed of light would be greater in the
second medium This corpuscular model of light was further developed
by Isaac Newton in his famous book entitled OPTICKS and because of
the tremendous popularity of this book, the corpuscular model is very
often attributed to Newton