Easiest way to do this is to simply cross your eyes, as if you're trying to focus on one of those "Magic Eye" images. It's a mild cheat and actually looks kind of neat.
I've used the same method on clerk exams where you have to sort out the differences between two given addresses (one misspelled, the other not).
I've used the same method on clerk exams where you have to sort out the differences between two given addresses (one misspelled, the other not).