Can you tell which of the 2 yellow lines is longer?
Do you think these diagonal lines are parallel to each other?
What about the red lines in this image — are they straight or curved?
How many colored spheres can you see here?
This is an Ames room. Which of these 2 people do you think is taller?
How many points do you think this trident has?
Can you tell which animal is hiding here?
Concentrate on one point of this image for at least 15 seconds. Don’t think about anything else. Keep looking. Can you see the image disappearing?
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