I normally wear glasses and today I tried on some glasses with no lenses in them.
Strangely enough things where quiet out of Focus like I had glasses on which where for long sighted people (and I'm short sighted). As my brain was used to wearing correct glasses it decided to compensate and make things look really bad.
I guess if I waited long enough my brain would get used to them having no lenses.. I just thought it was strange what the brain does.