What is the complementary color of red?

$(i)$ 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?

Name the component of white light that deviates the least and the most while passing through a prism.

Explain the following terms connected with the eye:
$(i)$ Ciliary muscles
$(ii)$ Accommodation
$(iii)$ Blind spot.

$A$ person suffering from an eye defect uses lenses of power $-1\, D$. Name the defect he is suffering from and the nature of lens used.

In the figure,a ray of light $PQ$ is incident normally on one face $AB$ of an equilateral glass prism. What are the angles of incidence at faces $AB$ and $AC$?