Exactly how are your eyes killing you? Sometimes when I work up close for a long time and "exercise" the muscles that move my eyes too much, the muscles hurt for a day or two or three. That's just like the first day you exercise after not exercisinc for God only knows how long.
I hope that's all it is.
Otherwise, yes, close work blurs the vision but for me it usually gets back to normal by the next day. It also makes them sting, which my Dr told me is because I don't blink enough when I'm very focused on something. Apparently, the surface of the eyes dry out.