Choose a point on the staircase. Follow the staircase clockwise, climbing the stairs until you get to a step that takes you back down........

I'm sure, by now, that you have realised that there are no steps going down! This is the never-ending staircase.

Pay particular attention to the horizontal lines in the image above. Are the aforementioned lines curved or striaght? Click on the image above will remove any distraction on this page.

Can you count the number of black dots? You may think that the answer is zero, but look closely. Look at a particular white dot - observe what happens to the surrounding dots. Then, as your eyes move to another dot, see what happens to the first 'white' dot.

Let your eyes follow the movement of the rotating pink dot, you will only see one colour, pink. Now, stare at the the black plus sign ("+") in the center of the image.

First, the moving dot turns to green. Then as you continue to stare, all the pink dots will disappear, and you will only see only a single green dot rotating. This can happen in different ways (including different ways for same person in successive viewings): Green dot "gobbles up" the pink dots (PacMan style) Dots disappear, but reappear briefly after being passed by green dot Dots in certain positions disappear quickly and dots in other positions can persist for several additional rotations of the green dot.Because this is an effect of neural fatigue, minor gaps in concentration can cause the circle of pink dots to reappear (and disappear again). Holding your visual concentration, shift your gaze away from the center of this image. The pink dots reappear, but you may also see a full circle of green dots centered on your new focus point.