Which movement is characterized by geometric forms and optical illusions?

The movement characterized by geometric forms and optical illusions is Op Art. This art form emerged in the 1960s and uses geometric shapes and patterns to create visual effects, often inducing feelings of movement or changes in perception for the viewer. Artists associated with this movement, such as Bridget Riley and Victor Vasarely, employed optical tricks that could challenge the observer's visual perception, making static images appear dynamic and pulsating.

Op Art's emphasis on optical experiences and the manipulation of color and form distinctly sets it apart from other movements. For example, while Art Nouveau is known for its organic forms and intricate designs, often inspired by nature, and Art Deco focuses on glamour, elegance, and functionality often with bold lines and angular designs, neither of them primarily incorporates the optical illusions that are the hallmark of Op Art. Folk Art, on the other hand, emphasizes traditional craftsmanship and cultural themes rather than the abstract, illusionary qualities found in Op Art.