Have you ever wondered how many megapixels our eyes are capable of? I have, and it turns out that we can see with the astounding detail of 576 megapixels. That is 30 times better than any HDTV. It is similar to a computer screen running with a resolution of 32,000 x 18,000 (try designing a fluid website layout for that...)
Each "picture" our eye sees is about 1.61GB of RAW data (or 249MB if it is saved as JPEG). It would take a high-end laptop about 2 minutes just to save the picture + the time it takes to do any kind of data processing -like pattern recognition, color and motion detection.
Our brain can do the same almost instantly. A test with USAF fighter pilots revealed that they could distinguish visual changes at a rate of 1/220th of a second - a frame-rate of 220 (that would be one hell of a gaming experience). Then imagine the speed of our perception when looking at the subconscious level...
Of course, without my glasses the only thing I can see is a 576 megapixel image of colored fog :)