NCERT Chapter 11“Human Eye and Colourful World” describes the fine structure of the human eye. It does explain the reason behind the colour of the Sun during the time of sunrise and sunset. It explains the accommodation of the eye concept. Various defects that occur to the eye like refractive defects of vision which include hypermetropia, myopia, and presbyopia. The eye loses its power of accommodation at old age. The splitting of white light into its component colours is called dispersion. Scattering of light causes the blue colour of the sky and the reddening of the Sun at sunrise and sunset.