@judgedread >Why would you?
Because its part of your anatomy which your body is using as an understood mechanism that you don't know how it works. There's a logical paradox there. As for stages of eye development. Those are isolated organ/cell structures from different animals presumed to have developed towards but not actually substantiated. Implication>Substantiation. It also doesn't explain why the "older" model is still around. Nor where the drive to have "light sensitivity" for the cell structure came from in the first place.