The rods and cones of the eye retinal layer are modified:

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

The 'adaptation' of eyes in the dark is due to

In the vertebrate eye,the transparent conjunctiva is formed from:

In vision,photons are converted into

The following figure is a diagram showing parts of the human eye. Identify $P, Q$,and $R$ from the options given below.
$\quad\quad P\quad\quad\quad Q\quad\quad\quad R$