The video presents a series of 10+ optical illusions, including a train that appears to switch directions, a hallway that seems to change speed, and a ballerina that spins both clockwise and counterclockwise. Other illusions include a blank space that isn't blank, a green circle that appears in place of a black plus sign, and a colored image that appears black and white. The video also features an iPhone hidden in a picture, an elephant with an unclear number of legs, and a photo that appears to have more people in it than initially meets the eye. The final illusion is a 20-second clip that makes everything around the viewer appear to be moving.
Here are the key facts extracted from the text:
1. The video discusses various optical illusions.
2. The first optical illusion is the train illusion, which can be seen as moving forwards, backwards, or switching directions.
3. Focusing on the furthest left side of the train makes it appear to move backwards, while focusing on the furthest right side makes it appear to move forwards.
4. The hallway illusion makes it seem like the viewer is moving down a hallway at a certain speed, but covering the sides of the screen can change the perceived speed.
5. The bulge effect is an optical illusion where a white light appears brighter when viewed from a closer distance.
6. Focusing on one of three yellow dots can make the other two dots disappear.
7. The spinning ballerina illusion can be seen as spinning in either direction, depending on the viewer's focus.
8. The pink circle illusion appears to have blank spaces, but focusing on a black plus sign reveals green circles in those spaces.
9. The building illusion can make a black and white image appear colored if the viewer stares at a dot in the middle of the image for 10 seconds.
10. The two pink circles illusion can make the circles appear to spin when the viewer moves their head forwards and backwards while focusing on a yellow dot.
11. The impossible trident illusion appears to have two or three cylindrical ends, depending on the viewer's focus.
12. An iPhone is hidden in a picture, and only a small percentage of people can find it.
13. An elephant optical illusion can make it appear to have four or five legs, depending on the viewer's perspective.
14. A picture appears to show two people, but a third person (a baby) is hidden in the outline of a tree.
15. A math exercise is presented, where the viewer is asked to perform a series of calculations to arrive at a three-digit number, with the first digit being the viewer's original number and the second and third digits being their age.
16. The final optical illusion is a 20-second video that can make everything around the viewer appear to be moving, even if it's not.