I'm told by an (admittedly pretty crappy-looking) online test (http://www.humanmetrics.com/cgi-win/jTypes2.asp) that I'm an INTJ, with strong NT, but only weak I and J components. I don't know anything about the Meyers-Briggs scale beyond what's stated about it in the wikipedia entry, but the result isn't surprising to me at all, as I can definitely sympathize with your propensity for missing "obvious" features in your surroundings.

This must be a common trait among engineers, too: one day I went to my engineering classes with exactly half of my face shaved, the other half having grown out for 2 weeks. About three people in my class noticed eventually and started laughing at me. Even with them laughing, the rest of my classmates didn't notice, and couldn't figure out what the laughing was about.