More Illusions to Test Your Visionhttp://articles.mercola.com/sites/articles/archive/2005/06/28/optical-illusion.aspxYour eyes can occasionally be fooled and you may perceive something that is really not there. We call these optical illusions and they can be an amusing break from our hectic schedules. According to common definition, an optical illusion is: A visuallyenCommunityServer 2008.5 SP1 (Build: 31106.3070)