1. Op Art
Op Art

2. Optical Art is a mathematically-theme form of Abstract art, which uses repetition of simple shapes and colors to create vibrating effects, foreground-background confusion, an exaggerated sense of depth, and other visual effects.

3. In the 1960's, the term "Op Art" was coined to describe the work of a growing group of abstract painters. This movement was led by Victor Vasarely and Bridget Riley.

4. KEK-EG-II Victor Vasarely
NEPTUM III Victor Vasarely

5. TER-UR-NB Victor Vasarely
RIVOTRIL Victor Vasarely

7. VERTIGO Victor Vasarely
VEGA-FEL Victor Vasarely

8. Fragment 3/11 1965 Bridget Riley

9. These dots are completely white.

11. "Rotating rays"
The outer ring of rays appears to rotate clockwise while the inner one counterclockwise

12. "The autumn color swamp"
The inset appears to move.

13. The floor appears to bulge out, though this image consists of only squares.

14. "Primrose's field"
This checkered background consists of squares but appears to wave. In addition, this figure also shows a waving motion illusion.

15. "Uzumaki ampan"
Concentric gray circles appear to be spirals.

16. "Rollers"
Rollers appear to rotate without effort. On the other hand, they appear to rotate in the opposite direction when observers see this image keeping blinking.

19. Day 1: