The disk should be placed on a flat surface and spun. When you stare at the centre for 15 seconds and then look away, whatever you look at begins to swirl in a most disconcerting way. The disk was invented by magician and optical illusion expert Jerry Andrus and produced by Binary Arts Corporation, Alexandria, VA 22314, USA. Copyright 1998 Binary Arts Corp.

The photograph cannot do justice to what you see when you view this bookmark. The silver spheres appear three dimensional and the red circle appears to be be below the actual level of the bookmark.

This is a fun application of a well known optical illusion. If you spin the disc clockwise on a table and look at its centre for around 20 seconds, and then look at the bunny sitting nearby, the bunny will appear to increase in size. Spinning the disc anti-clockwise will make the bunny look smaller. Made in China for Worldwide co, 3 Warple Way, London.

Inside the black dome are two parabolic mirrors which create a floating, 3D optical illusion of anything placed inside the Mirascope. The illusion is very powerful, although it is sensitive to angles. Made in China for TOBAR, Beccles, England. www.tobar.co.uk.

This special plastic sheet shows two optical illusions. Firstly, the concentric circles in the middle look anything but concentric. Secondly, the flat mat appears to be printed as a 3D mat: the 30mm border around the edges of the mat seem closest to the viewer, then comes the circular design in the centre of the mat, and further away still is the rest of the mat. It’s all very confusing! The concept is Copyright Paul Baars Design, Amsterdam. There are four place mats in this series – see also N2236, N2237 and N2238.

This special plastic sheet shows two optical illusions. Firstly, if you stare at the small cross in the centre, and move the mat towards and away from you, the circles appear to move in opposite directions. Secondly, the flat mat appears to be printed as a 3D mat: the 30mm border around the edges of the mat seem closest to the viewer, then comes the circular design in the centre of the mat, and further away still is the rest of the mat. It’s all very confusing! The concept is Copyright Paul Baars Design, Amsterdam. There are four place mats in this series – see also N2236, N2237 and N2239.