The Height Illusions - 9/52


I love optical illusions so I thought I would share a few of my favorite and with many people opting to take up 365 day challenges i thought i would try a 52 week challenge in which i will share with you a different Illusion every week. so if you have any you would like me to feature get in touch.

The Vertical-Horizontal Illusion (also known as the Bisection illusion) was created by Johann Joseph Oppel (1815 – 1894), a German mathematician and physicist. The Vertical-Horizontal Illusion was first published in the journal Jahresbericht des physikalischen Vereins zu Frankfurt am Main in 1855.

The vertical line appears longer than the horizontal line, even though both are of the same length.

It works the other way up too, and is sometimes called the T illusion.  It’s one of many illusions for which you’ll find a brilliant interactive demo on Michael Bach’s site.


The top hat illusion and the famous arc in St. Louis, USA, are considered as variations of the vertical-horizontal illusion since the height of the hat or the arc has the exactly same length as their base