When blue and yellow pigments are mixed and white light is incident on the mixture,which color of light is reflected?

What is the range of clear vision for a person with normal vision?

Name the colours of the visible spectrum.

Which part of the eye controls the amount of light entering the eye?

$A$ $14$ year old student is not able to see clearly the questions written on the blackboard placed at a distance of $5\, m$ from him.
$(a)$ Name the defect of vision he is suffering from.
$(b)$ With the help of labelled ray diagrams show how this defect can be corrected.
$(c)$ Name the type of lens used to correct this defect.

How is the eye lens held in its position?