The focal length of the eye lens increases when eye muscles

$A$ person is able to see objects clearly only when these are lying at distances between $50 \text{ cm}$ and $300 \text{ cm}$ from his eye. Identify the kind of defects of vision he is suffering from. Give reason for your answer.

Which lens is used to correct the defect of myopia (nearsightedness)?

$A$ near-sighted person can see only nearer objects.

Explain why,when the sun is overhead at noon,it appears white?

Where is the image formed in an eye suffering from near-sightedness?