I was looking at the traffic ect rather than the freaking grass.
Spotted the change in each of the examples near instantly. I'm not sure what that says about me...
Its not really testing how well you can see change, its testing how fast you can memorise a picture and compare it with a new one.
If there was no grey interval, your eyes would pick out the change after only 1 or 2 switches...
What a load of crap. Next time I'm stood waiting for a bus and the front window is 1% darker than yesterday I'll be sure to notice...