Illusion in art may feel like a recent phenomena, but it’s been around since cave paintings. With each new era, artists have used the tools and techniques available to astound audiences—and make them look twice. We’ve compiled six of the best tricks artists have used to create art that undermines the viewing experience.

1. Trompe l’oeil

Translating to “deceive the eye” in French, there’s no question that Trompe l’oeil gets the top spot. The term itself is broad, referring to any use of realism that creates an optical illusion, a trick that’s been in use for more than two millennia (see Zeuxis and Parrhasius’ battle of deception). Though it was used throughout the Renaissance, Baroque, and Mannerist movements, the heyday of trompe l’oeil was potentially in the 19th century, with the work of William Harnett gaining notoriety. His still lifes put a sharp spin on what we came to expect from art, both in subject matter and uncanniness.

2. Realism

Realism differs from trompe l’oeil in that there’s no sleight of hand aspect. But, just like trompe l’oeil, it relies as much on subject as it does technique. Take Georgia Peskett’s Thompson Street, Soho as an example. The green metal of the fire escape, the fire hydrant, the cook on break—not one of these objects is romanticized by Peskett’s brush. But the scene itself is part of the effect, too. For much of art history, a scene from everyday life was not worth painting. By choosing this side street as her subject, Peskett is, however briefly, letting us forget we’re in front of a painting at all—the essence of illusion.

3. Anamorphosis

Also called distorted projection, anamorphosis is the technique of making a work of art appear normal only when viewed from a particular angle or with a particular perspective. Search the term on Google Images and you’ll get mostly modern results, but the technique has been in use since before the Renaissance (and has even been seen in prehistoric cave paintings). One famous example is The Ambassaors (also called Jean de Dinteville and Georges de Selve) by Hans Holbein the Younger (1533). What seems like an oddly abstract streak at the bottom of the painting is actually a skull—just look at it by positioning yourself above and to the right of the painting (or below and to the left). The skull seems to be a memento mori (a reminder of death), but historians have presumed it to be more, given the use of the effect. Some have suggested its presence works within the three themes of the painting: the heavens, the living world, and death (the period in between the other two). Others have presumed it’s merely an optical illusion—one potentially used by Holbein to impress potential benefactors.

4. Banksy

Yes, the man deserves his own category. Banksy has had plenty of imitators, but none can hold a candle to the master of the look-twice aesthetic. Though he creates work that stands on its own, he’s perhaps most known for art that blends in (or sticks out) from a given environment. In Gnark Gnark Gnark! (2008), for example, Banksy works on three levels: first with the original graffiti (the rat), then with the realism of the worker painting over the graffiti, and finally with the rat coming to life, snipping the cord supporting the worker’s platform. By undermining our perspective, perception, and assumptions, Banksy seems to remove the ground on which we stand.

5. Giuseppe Arcimboldo

Like Banksy, Giuseppe Arcimboldo deserves his own category; he was practically an art movement in his own right. (Today, his style is often imitated without credit, and many of us can’t be blamed for assuming the technique was originally executed by many different hands.) Arcimboldo was most known for using fruit, vegetables, and plant matter to build human heads, though he occasionally deviated, such as in The Librarian (1562). His works varied in verisimilitude, from Flora (1589), which looks about as real as his portraits get, to Four Seasons in One Head (1590), a self-portrait made at the end of his career that throws realism to the wind. If anything, his work is indicative of Mannerism, in that it takes some liberties with Renaissance values, and chooses artificiality over naturalism.

6. Digital illusion

In the past 25 years (or more, really), the extent to which artists can bend our minds has proliferated profoundly. With a mix of artistry and tech know-how, artists are creating visual puzzles that simply can’t be solved. Unlike the above examples, what goes into the making of a given work is all but opaque. As just one example, take the mesmerizing works of Refik Anadol, a media artist born in Turkey. He is exploring “the space among digital and physical entities by creating a hybrid relationship between architecture and media arts with machine intelligence.” By often housing his work in a meta context—we see someone else enjoying his work—he makes us question what it can mean to view art. (And if there’s one commonality between all of the above examples, it’s exactly that.)