At noon,the sun appears white because:

How can a change in the size of the eyeball be a reason for $(a)$ Myopia and $(b)$ Hypermetropia? Compare the size of the eyeball with that of a normal eye in each case. How does this change in size affect the position of the image in each case?

What is the complementary color of red?

$A$ person is advised to wear spectacles with concave lenses. What type of defect of vision is he suffering from?

An old person is unable to see clearly nearby objects as well as distant objects. $(i)$ What defect of vision is he suffering from? $(ii)$ What kind of lens will be required to see clearly the nearby as well as distant objects? Give reasons.

When white light is incident on an object and it reflects all its constituent colors,what color does it appear to be?