Chinese scientists have invented a device that can easily detect a drug taker simply from the way his pupils react to certain rays.

The technology, developed by scientists in southwestern Yunnan province, has proved successful in six pilot projects in local villages, and have passed the assessment of the Ministry of Public Security, according to a source with provincial Department of Science and Technology.

In the tests, 891 cannabis smokers were mixed with 826 non-drug takers. The device was able to catch 93.94 percent of the addicts if they smoked the drug the day before the test, and 88.52 percent of them if they did it six days before.

No non-drug takers were mistaken for smoking the drug in the tests, scientists with the department said.

For addicts to opium or its related drugs, lights of certain wavelength and intensity make their pupils expand and contract, they said, adding that the new device can find out "how much a person is addicted to drugs."

The technology is obviously more advanced than similar detection techniques applied by police across the country, and it will be a good help if promoted nationwide, the scientists said.

Drugs are rampant in Yunnan, which is close to the notorious opium-producing "Golden Triangle" region.

The province has been designated as a target area for cracking down on the influx of drugs.

Source: Xinhua