Name the delicate membrane in the eye having an enormous number of light-sensitive cells.

What is meant by accommodation of the eye?

Which optical phenomenon is responsible for the early sunrise and delayed sunset?

$A$ prism $ABC$ (with $BC$ as base) is placed in different orientations. $A$ narrow beam of white light is incident on the prism as shown in the figure. In which of the following cases,after dispersion,the third colour from the top corresponds to the colour of the sky?

What is the other name of near-sightedness?

What would have been the colour of the earth's sky if there were no atmosphere?