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?
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.