I'm pretty sure only the prototype shockers came without an eye, and that it was always the intention for it to be vision.
I don't really understand what the big deal about the Impulse eye is - I have both an Impy and a Shocker, and if anything, the problem I have with the Impy eye (tho curiously not the Shocker one) is that it gets dirty easily, and when it doesn't see the ball, it doesn't let me fire.
Annoying as this is, it doesn't equate to a chop. In fact, the only time my Impy has chopped is when I've lent it to LJ and he turned the eye off... lol
I'm happy to acknowledge the fact that break-beam eyes might be better, but there are also several thousand impy-owners who would refute the claims that the sp eye is chop-city...