Only 1% can see the secret message inside the watch on the cover of this Comic book by Mark Millar called Chrononauts. Here's why and what it is... 

@mrmarkmillar/Twitter

Do you see the hourglass in the first picture? Or do you see nothing at all? Apparently, there is a condition that allows only 1 in 15 of us to see it. It's a semi-rare sporadic form of color blindness due to abnormal wiring in the occipital lobe. Duh! lol, basically that means you are a weird-o. No, you are just way more special than most of us. Did you see it? I saw faint lines but I couldn't make out an hour glass. Guess i'll just go back to staring at ugly striped dresses.