OPTICAL ILLUSIONS

The eye says it’s a flower, the brain thinks it’s a face. Carefully positioned images can cause discrepancies between the actual image and the perception created by the brain. Credit: Tom Wigley/Flickr, CC BY-NC-SA 2.0. Natural beauty

This garden in Paris is made up of grass at different heights and white lines. The area is oblong in shape, but from one angle it looks like a sphere. Credit: Jeff Hester/Flickr CC BY-NC-SA 2.0 BIGPICTUREEDUCATION.COM When the world was flat

Obscured horizons and the contrasting slopes of the landscape and trees often cause people to lose their bearing on this downwards ‘gravity’ hill. Credit: Ray/Flickr, CC BY-NC-ND 2.0 BIGPICTUREEDUCATION.COM Going up?

A photo of the whole monitor is taken with a hand in front of the screen, and is then set as the background on the monitor. The note is then opened over the top of the new background. Credit: Evan/Flickr, CC BY-ND 2.0 BIGPICTUREEDUCATION.COM I didn’t use Photoshop

This image appears to be moving; the brain detects movement, but this is actually triggered by black-and-white edges, through the use of curvature, colour and shape. Credit: Roman Soto/Flickr, CC BY 2.0 BIGPICTUREEDUCATION.COM Spiralling snakes

Figure–ground perception is the tendency to simplify an image into its figure (i.e. its main subject) and its background. Whether you perceive black or white as the figure determines what you see (i.e. vase-like columns or men talking). Credit: Sha Sha Chu/Flickr, CC BY-NC-SA 2.0 BIGPICTUREEDUCATION.COM Black or White?

The lines running from top to bottom appear tilted but are in fact vertical. Certain shapes and colours cause the brain to perceive movement in some situations, a phenomenon called retinal slip. Credit: ClintJCL/Flickr, CC BY-NC-SA 2.0 BIGPICTUREEDUCATION.COM Moving Triangles

Although this room appears to be cubic, it is actually a trapezoidal shape. The woman is actually standing much closer to the camera than the man. Credit: Ian Stannard/Flickr, CC BY-SA 2.0 BIGPICTUREEDUCATION.COM Our house

Two walls placed at very specific angles create what appears to be a complete building from a particular viewpoint. Credit: Thom Watson/Flickr, CC BY-NC-SA 2.0 BIGPICTUREEDUCATION.COM Could you live in this?

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