For unusual and unnatural effects, coloured light can be projected onto the eyes of the subject. 2 dedolights are used with imager projection attachments; equipped with an iris and colour filters.
This short excerpt is from the movie: THE LIGHT IN YOUR EYE.

Check out the full version in high res at dedo.tv

https://www.dedo.tv/video/the-light-in-your-eye/482518263/