1. Q17: Art as an Optical Illusion

2. Joseph Albers
Josef Albers (March 19, 1888 – March 25,1976, German born American abstract artist.

5. Alberto Biasi b. 1937

7. MC Escher
Maurits Cornelis Escher ( ) is one of the world's most famous graphic artists. His art is enjoyed by millions of people all over the world, as can be seen on the many web sites on the internet.
He is most famous for his so-called impossible structures, such as Ascending and Descending, Relativity, his Transformation Prints, such as Metamorphosis I, Metamorphosis II and Metamorphosis III, Sky & Water I or Reptiles.

11. Bridget Riley
Bridget Louise Riley CH CBE (born 24 April 1931 in Norwood, London) is an English painter who is one of the most famous Op artists.
She currently lives and works in London, Cornwall, and France.

16. Victor Vasarely
Victor Vasarely born Vásárhelyi Győző, 9 April 1906 – 15 March 1997 was a Hungarian–French artist whose work is generally seen as Op-art.
His work entitled Zebra, created by Vasarely in the 1930s, is considered by some to be one of the earliest examples of Op-art.
Vasarely died in Paris in 1997.

20. Kinetic Art

22. Optical Illusions