I mean, for me, in 2012 when I retired, it was more of a break than anything else because for so long, my head was staring at a black line and I couldn't do anything else. I was never a kid.

IF YOU STARE AT IT TOO LONG, YOU MAY HAVE A FLASHBACK TO YOUR RED LINE TRAIN. BREAKING DOWN UNDER THE PARK STREET STATION. >> COBY UNGER AN ASSOCIATE INSTRUCTOR AT MIT’S HOBBY SHOP. WANTED TO ...

Stare at this lady's red nose for 30 seconds and then look at a wall while blinking very quickly. This trick is called an Afterimage, or ghost image. Your eyes' photoreceptors and your brain aren ...