For hundreds of millions of people in China, the spread of the new coronavirus has caused abrupt changes to the smallest of habits -- even a gesture that most in the country are used to by now: Looking into the camera for facial recognition.

Residents donning surgical face masks while venturing outside their homes or meeting strangers have found themselves in an unfamiliar conundrum. With their faces half-covered, some are unable to unlock their phones or use mobile payments with their faces.

People wearing protective masks to help stop the spread of a deadly virus, which began in Wuhan, at the Beijing railway station on January 27. (Picture: Nicolas Asfouri/AFP)

“Been wearing a mask everyday recently and I just want to throw away this phone with face unlock,” said one frustrated user who posted on Weibo using an iPhone.

“Under the current circumstances, for the past two days, I’ve been basically wearing a mask all the time except while sleeping. In times like this, the iPhone’s Face ID doesn’t really work that well,” another user wrote, adding that she hopes Apple will bring back fingerprint unlock.

It’s more than just handset troubles, though. In China, facial recognition is being deployed from train stations and airports to stores and hotels. Some people say they now have trouble entering gated communities protected by facial recognition systems.

“Just came in through the community gate. I was standing under the facial recognition [camera] but it didn’t recognize me,” one user said. “Around two minutes later, I realized I was wearing a mask.”

Travelers wearing face masks at Hankou railway station in Wuhan in southern China's Hubei province on January 21. (Picture: AP)

The everyday use of surgical masks was a common sight in parts of China (and Asia) even before the current outbreak, when many wore them to shield themselves from pollution. Last week, a Huawei executive said the company considered enabling facial recognition for masked users while developing its 2018 flagship phone.

“We tested the mask-wearing scenario on the Mate 20 Pro,” wrote Huawei vice president Bruce Lee on Weibo. “But there are too few feature points for the eyes and the head, so it’s impossible to ensure security. We gave up on facial unlock for mask/scarf wearing. This is also why we still keep fingerprint recognition while supporting 3D facial recognition on our phones.”

For some people, though, facial recognition has become such an integral part of life that older technology now seems annoyingly inconvenient.

“I’ve gotten used to WeChat Pay’s facial recognition,” said one user. “I’ve been wearing masks these days. Not really used to changing to passcode payment.”

“Fingerprint payment is still better,” another wrote. “This facial recognition, I don’t even dare pull down my mask. And passcode comes so slow. All I want is to pay and quickly run.”

Still, as cases of illnesses and deaths from the Wuhan epidemic continue to spike, few people are willing to go maskless when traveling outside. In two days alone, Alibaba’s shopping site Taobao sold 80 million masks.

(Abacus is a unit of the South China Morning Post, which is owned by Alibaba.)

Some seem to find unexpected joy in wearing a mask. 

“Just wear a mask and a cap, and I only need a minute to get ready. Don’t even need to wear makeup foundation or wash my hair,” said one Weibo user. “The only downside is I can’t unlock my phone with facial recognition.”