In this excerpt from George Williams' "Natural Selection: Domains, Levels, and Challenges," which Dan Dennet quotes in "Darwin's Dangerous Idea," he writes: "A human eye blink takes about 50 milliseconds. That means that we are blind about 5% of the time we are using our eyes normally." However, I did the math based on 10 blinks per minute provided by laboratory settings, and I've concluded that we are only blind .5% of the time that we are using our eyes normally (if we omit 8 hours of the day for sleep). Anyone want to explain how Williams and Dennett came to 5%? Wouldn't this only apply if we blinked every second, which obviously we don't?
Source: http://books.google.com/books?id=nTJlZ9Q...=html_text
Source: http://books.google.com/books?id=nTJlZ9Q...=html_text
