At least 15 attendees of this year’s ApeFest event, which Yuga Labs is dedicating to the famous NFT collection Bored Ape Yacht Club, reported eye burns, writes Engadget.

People link the problem to the stage lighting at the event, which was organized in Hong Kong this year. Some attendees claim that doctors diagnosed them with photokeratitis, a medical term for damage to the outer layers of the cornea caused by intense ultraviolet radiation.

“Woke up in the middle of the night after ApeFest with so much pain in my eyes that I had to go to the hospital,” shared by Crypto June. “Doctor told me it was due to the UV from stage lights.”

Crypto trader Adrian Zduńczyk also attended the event and had to have his eyesight checked. In his case, there were no serious consequences, but the trader advises other participants not to hesitate and consult a doctor.

“To all my friends who suffer now: go get your eyes checked. You’ve likely most literally got your eyes burnt with UV like I did, which requires medications, eye drops, eye protection, antibiotics and specialist care. Don’t ignore this health hazard. Without proper treatment, it may cause long lasting vision impairment and other serious damage,” he wrote.

Yuga Labs has already responded to the situation. They said that they were aware of the problem and were communicating with some ApeFest attendees to identify potential root causes.

“Based on our estimates, we believe that much less than 1% of those attending and working the event had these symptoms.” the company added, and advised people who observe symptoms to seek medical attention.

Some people were outraged by Yuga Labs’ response to the situation. For example, one user posted an image of blurry text on the X platform that was impossible to make out and added “Fixed the post for you.”

The incident resonates with what happened in 2017. Back then, attendees of the HypeBeast party reported eye damage. Later it became known that the lighting contractor used lamps that are often used for disinfection.