I was listening to Jeremy Vine's programme today and heard 2 dreadful stories:
http://www.bbc.co.uk/programmes/b006wr3p
1) (at 1.38.36) concerning someone who wore her lenses whilst in a swimming pool and contracted an amoeba infection which has resulted in the loss of sight in one eye (which may or may not yet be recovered).
2) (at 1.53.15) concerning a woman who suffered an extreme fungal infection which resulted in having her eye removed 3 weeks ago. Apparently, according to the Infectious Deseases team at Addenbrookes and the DNA team at the National Fungus team at Bristol, the fungus was within the one day disposable lens which had been manufactured in Singapore and is sold by the UK's 2nd largest supplier.
I am not into scaremongering, at all, but it would seem prudent to check out the programme and links and look on the reverse side of boxes of such lenses as the country of origin is shown.