Questions along the lines of "Does a perfect X exist?" or "does an ideal Y exist?" are almost universally, unequivocally answered, "no." Unless there is no way for something not to be perfect (a photon will always be a perfect photon, and behave as such, because there is no way for a photon to be imperfect, as far as I know.)

"Perfect" and "ideal" usually mean "fits perfectly to a simple model" (and all our models are far more simplistic than what's actually going on). We make approximations, assumptions and take mathematical liberties that we use until the model stops giving reasonable answers, or the precision required for a task. Then we resort to more complex models, based on theory or just optimized with empirically determined parameters until we can solve the problem at hand.