Nearly 3 million people wear contact lenses in the UK, around 55,000 of them living in the catchment area of the hospital, including 30,000 serving hydrogel lens wearers and 1700 silicone hydrogel contact lens wearers.

But those wearing hydrogel lenses while they slept were five times more likely to be severe keratitis than those wearing silicone hydrogel lenses developed.’Those who choose to sleep in lenses should be advised silicone hydrogel lenses, which carry out a five times decreased risk of severe keratitis for extended wear compared with hydrogel lenses,’the authors conclude.However only two nine developing countries worldwide – East Asia and South-East Asian – are on the way in order to achieve the sanitary destination, to North African and Latin American a very close behind.