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: --
This is an optical illusion due to the properties of special relativity.
This motion may be an optical illusion caused by the relativistic velocity of the jet, and not true superluminal motion.
However, that is an optical illusion.
Or was it an optical illusion?
That is the optical illusion which will not survive its exposure during the debate tonight.
We ask for the so-called optical illusion of the level playing field.
If we consider them as public expenditure cuts, we find that they are very largely an optical illusion.
To say that this process incurs an extra cost for pension funds is an optical illusion.
