South Korean beauty conglomerate Amorepacific, which owns popular labels such as Laneige and Sulwhasoo, has seen sales for its sleeping masks triple in the last five years.
These are face masks which can be applied and worn throughout the night - as opposed to masks that are applied for only 15 to 20 minutes - to hydrate, brighten and refresh the skin.
In a recent interview with The Straits Times, Mr Brian Suh, senior vice-president and research director of the skincare research division at Amorepacific in South Korea, says the beauty giant pioneered the skincare product in South Korea in 2002 - with the popular Laneige Sleeping Mask, which has since sold more than 30 million units.
He adds: "There is an old Korean proverb that says, 'To be a beautiful person, you need to have enough sleep'. Research has shown that people with enough sleep and people who are sleep-deprived have different skin conditions."
Indeed, sleeping masks have taken beauty sleep to a different level.
Mr Suh, who has been with Amorepacific for 16 years, explains: "We created this sleeping mask also because the skin recovers faster during the night. The golden hour (the optimum time for the skin to renew) is between midnight and 1am.
"So it's also a good time to moisturise and purify the skin. That is when it can absorb and recuperate the most."
Mr Suh adds that these masks also help people to save time.
"People are busy now, so we wanted to fully utilise the time when people are asleep to help them nourish the skin."
Sleeping masks are also available from other beauty brands, including Japanese label Shiseido, American cosmetics brand Kiehl's, French label Dior and beauty label Fresh.
Since Laneige Sleeping Mask, Amorepacific has also introduced sleeping mask products for its other brands, including Hera, Mamonde, Etude House, Innisfree and Sulwhasoo - all of which are available in Singapore.
The company also has sleeping masks that target specific areas such as the lips and the eyes.
Fans of Amorepacific sleeping masks say the products are easy to use and provide fuss-free skincare.
Retail manager Nicole Wong, 24, says she uses a sleeping mask almost every night. Her favourites include the Mamonde Enriched Nutri Sleeping Mask and the Lip Sleeping Mask from Laneige.
"Since I'm usually in an air-conditioned environment, my skin gets really dry. I don't like wearing a lot of moisturiser when I'm awake because it tends to feel heavy on my skin.
"So I like that I can just put on the masks, go to sleep and forget about it while it works on my skin."