The red and blue lines below span the diameter of two spinning helicopter rotors.  When you first look at this image, which line appears to be the longest?  Try measuring the two lines to see if you were right. This illustration was drawn by the talented Gianni Sarcone.

All of the edges in this image are straight and either horizontal, vertical, or at a 45° angle.  Does it appear that way to you? Edit:  I just also noticed that if you move your scroll bar up and down when viewing this image it appears to have some motion elements to it.

This is an excellent example of the way in which our eyes deceive us.  In the street view shown below, the line AB looks to be much longer than line CD.  If you measure them, however, you will find that they are exactly the same length.

In the image below, the red object on the bottom looks significantly larger than the orange object on the top, right? Continue reading the full post to find out if you are correct.

Do the two pillars on the Golden Gate Bridge appear to be parallel or skewed? Continue reading this post for the answer and additional information about this illusion.

Does that matchbox on the left appear to be the exact same size as the one on the right? They certainly do not look to be the same size, but they are.  This animation was created by Digitalvaho/Fred van Houten after being inspired by an article written by Bruno Ernst.  It is a variation of [...]

Presented below are three sport utility vehicles parked in a row.  Which one is the biggest? Would you believe that all three of these are identical and exactly the same size?  Perhaps you’ll want to measure them with something to find out for yourself. Remember, new illusions are posted daily Monday through Friday.  If you [...]