Alright, we tricked you. It is a test of patience. Can you hold out for 30 seconds?
This is exactly the time it takes to notice a wolf – if you stay within half a minute, then know that you are among the 20% of people with exceptional vision, who, moreover, know how to concentrate on the stain.
Start a stopwatch on your smartphone or count slowly yes to 30.
QUESTION 1 OF 1

Yes!
No, show me.