Which optical phenomenon is responsible for the formation of a mirage?

How is the eye lens held in its position?

When do we consider a person to be myopic or hypermetropic? Explain using diagrams how the defects associated with myopic and hypermetropic eye can be corrected?

$(i)$ What is meant by dispersion of white light? Draw a diagram to show the dispersion of white light by a glass prism.
$(ii)$ Light of two colours $A$ and $B$ pass through a prism. $A$ deviates more than $B$ from its path of incidence. Which colour has a higher speed in the prism?

$A$ glass slab is placed over a page on which the word $VIBGYOR$ is printed with each letter in its corresponding colour. $(i)$ Will the image of all the letters be in the same place? $(ii)$ If not, state which letter will be raised to the maximum. Give a reason for your answer.

What is meant by the spectrum of white light?