To my collection on on #visualperception , visual phenomena and #opticalillusion I just added the Pulfrich effect https://michaelbach.de/ot/lum-Pulfrich/ . You just need a dark filter (e.g. sunglasses) over one eye and watch.
It's certainly not new – but I just gave my “emeriting lecture” at my university with lots of live experiments, and one was a large Pulfrich pendulum. That reminded me to add it to my collection. Most of you will have access to a pair of sunglasses :).