0 something that tricks your eyes and makes you think you see something that is not really there, or see it differently from how it really is
1 something that you think you see, but that is not really there:
For example, some scientists believe that a zebra’s stripes are not for camouflage but to make an optical illusion.
The ostensible exile of beliefs about the supernatural out of written into oral culture increasingly looks like an optical illusion for the same reason.
It is, after all, an optical illusion, like the young girl-old woman picture.
In many ways it is, however, a social optical illusion.
It appears that the imperialist enterprise in recent centuries has been predicated on racial divisions: an 'optical illusion' that uses the metaphor of colour as a code.
I am advised that the diagram printed with both articles is very little more than an optical illusion and that it has no scientific basis.
This is in fact an optical illusion because it will not be the largest authority.
I would venture to say that anyone who cannot see through this optical illusion needs more than his eyes examined.
