The Human Eye and the Colourful World

This chapter explains how the human eye works as an optical instrument, its power of accommodation, and the common defects of vision (myopia, hypermetropia, presbyopia) with their correction using spherical lenses. It then applies the ideas of refraction and dispersion to natural phenomena: refraction of light through a prism, dispersion of white light and rainbow formation, atmospheric refraction (twinkling of stars, advance sunrise and delayed sunset) and scattering of light (the blue sky and the reddening of the Sun).