My nose has literally hit the screen before when trying to get the damn thing right. I'm not sure why we even need one, these are not the codes that launch nukes or anything.
I'm also not sure why we need one (if we have locked the payout address, that is) and it's a pain.
But have you tried zooming in to get a magnified view? If your mouse has a scroll wheel, hold the Ctrl key down while rolling the wheel to zoom in or out. Ctrl + and Ctrl - also zoom, and Ctrl 0 (zero) restores to the default.