A low-energy laser is applied to the iris to disrupt the brown pigment . This causes body to trigger 'scavenger cells ' to remove dark colours . Process takes 30 seconds , and the next few years eyes will become blue . 17 patients in Mexico and 20 in Costa Rica have undergone treatment . Process , which is undergoing clinical trials , has raised safety concerns .
A low-energy laser is applied to the iris to disrupt the brown pigment . This causes body to trigger 'scavenger cells ' to remove dark colours . Process takes 30 seconds , and two weeks later eyes will become blue . 17 patients in Mexico and 20 in Costa Rica have undergone treatment . Process , which is undergoing clinical trials , has raised safety concerns .