Scientists have warned contact lens wearers against a deadly bug, which can ultimately make them blind. It has been explained that Acanthamoeba parasite erodes the eyeballs, thus making the user blind.

There are several sources, which promote the growth of the parasite, including dust, sea water, showers and swimming pools, thus posing a potential threat to the eyesight of millions of those using contact lens around the world. In Britain alone, as many as 3.7million people use contact lens.

The parasite has been proposed to be feeding on bacteria left on contact lens, which are dirty. The user, when wears their lens, the parasite starts eroding the cornea, the outermost shield of the eyeball.

Fiona Henriquez, of the University of the West of Scotland, said, "Symptoms include itchy and watery eyes, blurred vision, sensitivity to light, swelling of the upper eyelid and extreme pain".

The infection caused by the parasite is although minor, its treatment is very complex, which takes a long time; it is painful and also there are no chances that it will be completely effective, thus leaving many Britons sightless each year. Dr. Henriquez asserted that this is a major problem that every contact lens wearer might have to face.

She along with Professor Craig Roberts, of the Strathclyde University, is working to develop more efficient lens cleaning solution.