Health experts have warned contact lens users that washing their lenses in tap water could increase the risk of being infected with an eye-devouring amoeba that can lead to complete blindness.

University of the West of Scotland's Dr Fiona Henriquez said that acanthamoeba is found in large quantities in tap water, lakes and ponds. She added that people who did not clean their lens properly or placed them in dirty cases were at a high risk of getting infected with the amoeba which could lead to blindness if it manages to get deeply embedded into the corneal tissue.

"It is a potential problem for every single contact lens wearer. The incidence is quite low but that may be a problem with diagnosis. There are no effective drug treatments. The drugs used are often ineffective and its a very brutal regime. It requires hospitalisation and topical applications of a toxic substance to the eye. We're trying to improve the elimination of this parasite and prevent blindness", she said.