You know how us driving instructors are always going on about looking carefully when pulling out of a junction, or when approaching a roundabout? Did you know that your eyes (and your brain) can be easily fooled?
This Wikipedia article explains how your eye can easily miss some important information. It has an interesting blind spot test – you should try it!
The image below has pairs of dots in each corner – unless you look at the centre of the image, in which case there is only one dot at the corners.
It’s all too easy to take a quick glance at a junction, and go, when a more thorough scan of the road might save you a lot of hassle!
Check out some more illusions here.