Ten well-documented perceptual effects, each drawn here from its own rules rather than copied from anybody’s picture. Every one of them comes with a way of proving to yourself that the thing you are seeing is not on the screen — a ruler, a mask, a switch that turns the trick off.
Where the explanation is still argued about, it says so. Several of these have been known for a century and a half and are still not fully settled, which is a more interesting fact than any of the tidy explanations that get repeated about them.
Nothing here is anybody’s artwork. These are the underlying constructions — a grid, a set of gradients, a pair of arrows — drawn to their own published rules with this page’s own numbers. Many of them exist in famous versions by particular artists and researchers; none of those versions is reproduced here.
If any of them does nothing for you, that is worth knowing rather than a failure. The peripheral drift effect in particular does not work for everybody, is much weaker on a static screen at close range, and stops entirely if you look straight at it — which is the effect, not a fault.