What experiments can be used to detect the functions of the pupil and lens?

The function of the pupil is to regulate the flow of light entering the eye, depending on the lighting. To observe this, you can follow the change in its diameter leaving the illuminated room into the corridor and vice versa.
The function of the lens is to focus the rays reflected from the object onto the retina. Take a piece of paper. make a hole in it and write a word around it. Now observe the clarity of his vision when you look at a word or, through a hole, at some distant object.