Cigarette vending machines in Japan may soon start counting wrinkles, crow's feet and skin sags to see if the customer is old enough to smoke.

The legal age for smoking in Japan is 20 and as the country's 570,000 tobacco vending machines prepare for a July regulation requiring them to ensure buyers are not underage, a company has developed a system to identify age by studying facial features.

By having the customer look into a digital camera attached to the machine, Fujitaka Co's system will compare facial characteristics, such as wrinkles surrounding the eyes, bone structure and skin sags, to the facial data of over 100,000 people, Hajime Yamamoto, a company spokesman said.

"With face recognition, so long as you've got some change and you are an adult, you can buy cigarettes like before. The problem of minors borrowing (identification) cards to purchase cigarettes could be avoided as well," Yamamoto said.

Japan's finance ministry has already given permission to an age-identifying smart card called "taspo" and a system that can read the age from driving licenses.

It has yet to approve the facial identification method due to concerns about its accuracy.

Yamamoto said the system could correctly identify about 90 percent of the users, with the remaining 10 percent sent to a "grey zone" for "minors that look older, and baby-faced adults," where they would be asked to insert their driving license.

Underage smoking has been on a decline in Japan, but a health ministry survey in 2004 showed 13 percent of boys and 4 percent of girls in the third year of high school -- those aged 17 to 18 -- smoked every day.

(Reporting by Yoko Kubota; editing by Miral Fahmy)