Here are a few quotes:
The reason we don’t see our own typos is because what we see on the screen is competing with the version that exists in our heads.
By the time you proof read your own work, your brain already knows the destination. This explains why your readers are more likely to pick up on your errors.
As any typist knows, hitting keys happens too fast to divert a finger when it’s in the process of making a mistake.
... if you want to catch your own errors, you should try to make your work as unfamiliar as possible. Change the font or background color, or print it out and edit by hand.
