The easiest way to explain it is this:
In short, The Pupil allows light to strike the retina
The Iris is responsible for controlling the diameter and size of the pupil and thus the amount of light reaching the retina
Iris is also the name of the program that aims to save and protect your eyes while in front of the computer
It reduces the amount of blue light that your screen emits and removes the PWM flicker (which is essentially your monitor turning on and off thousands of time per second), so you can feel less eye pain and sleep better
