Optical illusions are all around us. Most are created in nature and some are man-made. A fun project to try, courtesy of SF Globe, is drawing your hand in 3-D. For this you will need a piece of paper and some markers and of course a hand.
This project is also good in helping develop young children’s motor skills. Start by tracing the hand with a light color so that it lightly shows up on the paper. Then start with your horizontal lines across.
Create a small arc when you come to the first line of the hand and continue the arc on to the next line of the hand. Do this each time you encounter a line from the hand drawing. Once complete, you should be able to see a 3-D outline of the entire hand.
When you draw your hand using breaks in the line it causes your eyes to believe they are seeing a 3-D object. Optical illusions work by relying on the way our eyes interpret visual information.
Neurons within the eyes are responsible for determining how edges are formed of a viewed object. That information is used to build the shape of the object. Our eyes then believe that the object is 3-D.