...at the same time.

So it's not like random mutations are occurring in a vacuum that are resulting in the formation of the eye.

Those mutations are occurring at the same time that OTHER mutations are occurring that are moving towards whatever - longer necks, better hearing, longer fir, wings, whatever.

So all of those mutations are occurring, at the same time, with some animals dying that don't have some of them, some dying that have a few but not all, some passing on the genes, some not.

Even over hundreds of billions of years, I don't see how that can get you from a single cell organism to what exists today.