That's an interesting article...
However, they say
the effect of overnight OK lenses on corneal shape is temporary, and wears off over a few days if the lenses are not worn. To maintain the optical effect, lenses must be re-inserted and worn every night (or in some cases, every 2nd or 3rd night).
which is a quite different timescale to what I was told by one optician in Brighton selling them; he said the timescale they work on is weeks, not days.
Scarring is surely only from infections?
There is another aspect of this: if you sleep on your side, and the pillow pushes against your eye, that could squash the eye in the same way. I normally sleep on the RH side and sure enough my right eye has much more astig than the other. I wonder if anybody else notices this. It might explain why it sometimes appears that one's last eye test was duff; the resulting glasses don't work properly despite having spent a few hundred quid on them. Of course opticians normally blame crap eye tests on Specsavers...
