Acanthamoeba keratitis is a rare eye infection caused by a water-borne microorganism, Acanthamoeba, which infects the cornea. The disease is rare but has a strong association with soft contact lens wear. Since 2011, there has been a threefold increase of the infection in South-East England. In this interview, David Cartwright speaks to Dr Nicole Carnt, at the University of New South Wales Sydney, to find out what the reasons are for the increased incidence in the UK and what this means for optometrists.