Virus-killer UV lights burn people’s eyes, doctors warn

Ultraviolet lamps intended to kill viruses and bacteria seem to cause discomfortunate eye damage in some people. In a new article this month, doctors report several cases where people have developed inflamed corneas due to UV exposure from “germicidal lamps” put in place during covid-19 pandemic. Some patients weren’t even aware the lamps had been installed.

UV lighting has gained a lot of attention lately, since the radiation can degrade the stability of many germs. Sspecialized lamps have been used in the past to control outbreaks of other potentially airborne diseases, including tuberculosis. Now a lot companies and hospitals use UV light to disinfect parts and equipment.

The problem is that UV rays can harm humans too., as anyone who has ever had a sunburn knows. Eexposure to UV rays can damage both our skin and our corneas, the transparent and protective outer layer of our eye. When this happens, it causes painful inflammation called photokeratitis.

In this new paper, published in the journal Ocular Immunology and Inflammation, the authors describe seven cases in which people developed photokeratitis several hours after exposure to UV lamps. All cases were seen by doctors at the Bascom Palmer Eye Institute at the Miller School of Medicine at the University of Miami.

In addition to the irritation and redness, some patients have experienced mild symptoms such as feeling like something stuck in their eyes. Others presented with severe and painful burns and sensitivity to light. In three cases, the lamps had been installed at home, while three of the patients had been exposed at work. In all of these cases, patients reported having been in direct contact with the light without eye protection. (a sevenh case involved a person exposed to UV light in a dentist’s office).

Fortunately, people’s symptoms were short-lived after treatment – usually a combination of lubricating eye drops, antibiotics, and steroids – and most fully recovered in two or more three days. But these wounds are not the first of their kind to be seen during the pandemic. Earlier in April, the authors noted, doctors from Hong Kong reported three similar cases in a single household.

It’s not clear if UV lighting was really that helpful during this pandemic. Sufficient UV radiation should be able to kill the persistent coronavirus in the air or on surfaces and objects, as the protective masks used by health workers. But the exact type of UV radiation that is most effective at killing viruses (UV-C) is also very dangerous to humans, limiting how useful this disinfection is the strategy can be in the real world. The World Health Organization is now explicitly warning people not to disinfect using UV lamps for the same reason.

“Installing UV-C air disinfection in medical facilities requires well-trained technicians to avoid direct exposure of occupants,” the doctors wrote. “The authors advise all people to avoid direct exposure to UV-C germicidal lamps and to closely follow the manufacturer’s recommendations.”

While this current study is not intended to weigh in on the effectiveness of UV lamps for preventing covid-19, it does reinforce the reason people should be careful with them at all times.