They had eyes because why, again?
*sigh* You can’t possibly be that dense, can you?
It’s not a riddle.
It is a serious question. Why would a critter living before there was any light have eyes?
In the total nonexistence of light eyes are a major liability, easily injured, easily infected, and a straight path to the brain for any number of parasites and pathogens.
In the total nonexistence of light a Cro-Magnon wouldn’t even know to blink to keep sand out.
Do try to think through the implications of what you assert, it’s much more intellectually honest than having to pretend to ridicule a serious point when someone points out an obvious non sequitur.
I ask again, if light had never existed, why would eyes exist?
I would like to think that you really can do better than to dismiss the question.
Unless you can’t, In which case please do feel free to mock the question and/or ignore it.