of the Month #17: Sept-Oct 2011 Back | Home
this page you can test your visual ability with interactive
optical illusion challenges. Each month, we
will post new puzzling illusions to solve and/or to
comtemplate: ambiguous and completion figures, impossible
figures, hidden objects, illusions involving colors,
geometric illusions, illusory moving patterns, verbal
illusions and paradoxes.
these illusions were adapted/designed by the authors
with the aim of allowing the visitor/reader to:
• discover how we
• test and enhance
the power of observation and critical thinking skills,
• improve mental flexibility,
• have fun being deceived
by puzzling visual challenges.
You can use the SVI
feature below in your non-commercial webpage
for free as long as you leave the copyright and
author's info intact and link to
a look at the colored surfaces of the R's...
Two of them are congruent, that is they
coincide exactly when superimposed. Which ones?