Open thread - Tuesday

I love optical illusions. Here's a selection of cool ones. Please follow the instructions above each picture to get the full effect.

Move head away then closer to the screen. Colours seem to enlarge

This one needs no action. Black dots flash into the spaces, all by themselves.


Move your eyes. The central circle seems to be alive.

This one is fun...

Move your eyes around and see the colours melt.

Focus on the yellow dot in the middle. The blue dots seem to fade and disappear.

Move your head slowly sideways until you can see the time stamp in the centre.

These are impossible windows. It's great fun to see the perspective
change, depending on how you look at it.

This last one is for Austin, but he may be disappointed...

[H/T to reader P.M.]