Which color is produced by mixing blue and red?

State one function each of iris,pupil,and cornea.

$A$ myopic person has been using spectacles of power $-1.00\, D$ for clear vision. During old age,he also needs to use separate reading glasses of power $+2.00\, D$. Explain what may have happened to his eyesight?

Why can you not see an object clearly if it is placed very close to your eye?

What is the complementary color of red?

When white light is incident on a yellow pigment,which colors of light are reflected?