Wearing contact lenses has its benefits, but these visual aids may harm individuals if they’re not properly handled. New findings published in the British Journal of Ophthalmology reveal that contact wearers in England contracted a rare eye infection called Acanthamoeba keratitis, reports the University College of London (UCL).

Acanthamoeba keratitis occurs when the cyst-forming microorganism Acanthamoeba infects the eye, causing the cornea to become painful and inflamed. In extreme cases, this the infection can lead to a partial or complete loss of sight.

For the study, researchers at UCL and Moorfields Eye Hospital in London reviewed hospital data from 1985 to 2016 and noticed a rise in the rate of the eye disorder. Scientists also noted a threefold increase in Acanthamoeba keratitis in southeast England since 2011 and believe the uptick applied to England overall.

Additionally, the team conducted a case-control study of 63 lens wearers with Acanthamoeba keratitis and 213 without the infection. (All wore reusable contact lenses daily.).

After participants completed a questionnaire, researchers found that those at highest risk for the illness were those with poor contact lens hygiene. Specifically, this included individuals who didn’t always wash and dry their hands before handling lenses, those who wore contacts while swimming in pools or soaking in hot tubs and people who used a particular lens disinfectant that has since been discontinued by the manufacturer. (However, scientists didn’t attribute any single one of these isolated risk factors to the outbreak of the disease.)

“We now need to share this information as widely as possible with clinicians, contact lens practitioners and contact lens wearers, a strategy that has proved effective in the past in decreasing the incidence and burden of this severe eye infection,” said Nicole Carnt, PhD, a researcher from the University of New South Wales, UCL Institute of Ophthalmology and Moorfields Eye Hospital and the study’s first author.

To avoid the contamination of lenses as well as their storage cases, experts recommend that contact wearers observe scrupulous sanitation practices. In addition, researchers suggest that folks not swim, wash their faces or bathe with lenses in place and consider wearing daily disposable lenses, which may be safer than the reusable kind.

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