Add this to the list of, well, conditions that I have. That many writers have. That, indeed, all copyeditors and proofreaders have. All of them. (All of them worth their salt, anyway.) Proofer's Eye means that you can never just read for pleasure. The slightest misplaced comma stabs you in the gut. The odd-one-out verb tense is like lemon juice on a canker sore.
It means that entire conversations get completely derailed when walking down the street, barraged by signs and ads, if any word is inappropriately capitalized.
It means that you find markedly less humor in lolspeak, because why would anyone in their intelligent right mind ever type like that?
You don't necessarily have to be a grammar nazi, lashing out and taking everyone to court for their mistakes. Proofer's Eye encompasses the more private heartaches and bitter tears shed in your own living room. But it does exist, and it is a problem.
Please, if you know someone with this debilitating disorder, do your part to help them out. Don't forget your apostrophes. Don't write non-poetic fragmented sentences. Do murmur tacit agreement when they shake their head. Don't let them tear their hair out.
Be there for them, not they're for them.
(These statements not endorsed by any creators of the DSM-V, although I was quite intrigued when it was recently released...)