San Francisco, Nov 23 (IANS): A US medical company is promoting a new laser surgery for people who want to permanently change their eye colour to blue.

California-based Stroma Medical has helped at least 37 patients to change their eye colour from brown to blue with a laser surgery in around 20 seconds, reports Xinhua news agency.

The laser works to eliminate the brown melanin -- the pigment which dyes hair and skin -- from the surface of the iris.

Without the brown melanin, when light consequently enters and scatters in the stroma, the blue colour appears.

In an earlier interview with CNN, the company's representative Gregg Homer said the laser is so weak that the eyes won't bear injuries from it.

Nevertheless, the medical industry and ophthalmologists still raised concerns about the irreversibility of the surgery.

The surgery costs $5,000.

However, the new laser is in clinical trials, Stroma Medical said.

Earlier media reports said the new technology is yet to gain approval from US regulatory bodies.