Dr Gregg Homer of Stroma Medical, a clinical equipment company based in California, claimed his new “Lumineyes” treatment could be a permanent alternative to coloured contact lenses.
The treatment uses a laser to remove melanin, the brown pigment, from the upper layer of the iris, leaving the blue colour free to replace it within two to three weeks of the procedure.
But the process is irreversible because the melanin will not grow back and can not be replaced.
Brown eyes, the most common type across the world, appear so because of the layer of pigment at the front of their eye.
People with blue eyes also have melanin, but it is concentrated at the back of the iris rather than the front, meaning the eye absorbs longer wavelengths of light while reflecting shorter ones.