This app is in Swedish, but you can probably figure it out :)

Is the eyes the mirror to the soul?
Well, there are many reasons why Health Professionals are looking into peoples eyes. This tool was developed to help you expand your own knowledge of pupil contraction. It will give you the time it took for the pupil to contract.

Uses your phones camera to catch the movment of the pupil and then shines a light on it while recording it. The images is processed into binary image files and discarded when your done.