The focal length of the eye lens increases when eye muscles

The figure below shows a glass prism placed in the minimum deviation position. $A$ ray of monochromatic light is incident on its face $AB$. Copy the diagram and show the refracted and the emergent ray. Mark the angle of deviation. State any two factors on which the angle of deviation depends.

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

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

Which color of light is scattered the most due to the atmosphere?

$A$ person can see distant sign boards clearly but cannot read clearly a book which is at $25\, cm$ from his eye. Giving reason,identify the defect. Draw a labelled ray diagram to illustrate this defect and its correction.