More than 20 people have reported burning eye pain and vision problems after attending a party for NFT owners in Hong Kong last weekend, the organizers said on Tuesday.

The gathering was part of ApeFest, a three-day event hosted by Bored Ape Yacht Club, a group of cryptocurrency enthusiasts who own unique digital images of primates that cost tens of thousands of dollars apiece.

Yuga Labs, the parent company of Bored Ape Yacht Club, is in contact with 22 people who had eye problems after the event, said Louise Conroy, a spokeswoman for the company.

“We are very distressed by these reports,” Ms. Conroy said in an interview, adding that Yuga Labs was working with an independent firm to investigate the claims. “Regardless of the outcome of the investigation, we intend to do the right thing by our community members.”

Although the exact cause of the symptoms had not yet been determined, she said, there were some potential culprits: “At this point, we’re looking into fluorescent paint in one of our setup areas, and most definitely looking at UV light.”

An estimated 2,500 crypto enthusiasts gathered at Kai Tak Cruise Terminal on Saturday night for a night of drinks, music and mingling that ended just after 11 p.m.

Adrian Zdunczyk, 30, a cryptocurrency trader who lives in Portugal, said that a sharp, fiery sensation in his eyes awoke him around 4:30 the next morning and that the feeling would not go away no matter how many times he rinsed his eyes with water. “It felt like microwaving your eyes,” he said on Tuesday.

Over the weekend, he saw social media posts from others reporting nearly identical symptoms: intense eye pain, vision problems and irritated skin similar to sunburn. Chloe Ge, another attendee, told The Financial Times that at 3 a.m. on Sunday she felt like her eyes were “being burnt with spicy chili.”

Dr. Will Flanary, an ophthalmologist in Portland, Ore., said that the symptoms being described on social media pointed to “a classic case” of photokeratitis, or damage to the cornea caused by ultraviolet light.

The condition is similar to “snow blindness,” the eye damage experienced by skiers exposed to UV light reflected off snow, he said. The condition is serious, but usually heals within 24 to 72 hours.

“It’s excruciating pain,” he said. “It’s 10-out-of-10 pain. But no, they won’t go blind from this.”

It is not clear where attendees may have been exposed to ultraviolet light. Images and videos from the event show a stage with a D.J. booth where neon purple lights were directed at the crowd. In another room, tubular lights mounted on the ceiling shone onto several decorative toilets where attendees paused to take photos.

Mr. Zdunczyk was told that he had photokeratitis at an eye clinic in Hong Kong on Monday. He was given lubricating eye drops and his symptoms have vastly improved, he said.

Still, he feels frustrated by the experience. He said he had paid the cryptocurrency equivalent of around $100,000 for a Bored Ape NFT and, with it, membership in a prominent community of crypto enthusiasts. Although he has exchanged emails with Yuga Labs representatives about his ordeal, he feels that the company has not taken the situation seriously enough. “It would have been better if it didn’t happen,” he said.

Bored Ape Yacht Club is one of the best-known collections of NFTs, or nonfungible tokens. Each member used cryptocurrency to purchase one of 10,000 distinct digital assets, which in this case are cartoon images of apes with accessories like cigars.

Bored Ape Yacht Club became broadly known amid a craze for digital artwork that gained steam in 2021, thanks in part to celebrity endorsements. In January 2022, Jimmy Fallon and Paris Hilton showed off their Bored Ape NFTs on “The Tonight Show.” “We’re both apes,” Mr. Fallon said, holding up a cartoon monkey wearing heart-shaped sunglasses. “I love it.”

The market for cryptocurrency and NFTs has cooled significantly since. The price of the least expensive Bored Apes had fallen to just over $50,000 in July, according to CoinDesk, an online publication that focuses on digital currencies. Just last year, the cheapest Bored Apes were selling for more than $400,000. Both Mr. Fallon and Ms. Hilton were later named in a class-action lawsuit alleging that Yuga Labs conspired with celebrities to defraud investors.

But Bored Ape Yacht Club has still sought to drum up enthusiasm among its members through ApeFest, its annual meet-up. The first ApeFest was held in 2021 in New York; the second, also in New York, featured a performance from Lil Wayne.

ApeFest this year was held in Hong Kong, which is vying for the attention of the international crypto community. Attendance was free for owners of Bored Ape NFTs, and $269 for plus-ones.

A website for the event promised “Three days of meet-ups and mayhem,” followed by “one big night full of surprises.”