Thirty-seven patients in Mexico and Costa Rica have successfully undergone a special laser procedure to change the colour of their irises from brown to blue. Conducted by a California-based company called Stroma Medical, the procedure costs $5,000, and right now can only be performed in certain countries outside the US. The company is yet to be granted approval from US government officials to practice the procedure locally.
How is all of this possible? Our eye colours are pretty fascinating things, we don’t get them from cells that are pigmented brown, blue, or green, but rather from the very specific structures that make up the two layers of our irises – the epithelium at the back and the stroma at the front. As ScienceAlert editor Fiona MacDonald wrote back in December, the colour of our eyes depends on how the black-brown pigments in our incredibly thin, two-cells-wide epitheliums interact with the dark pigment called melanin in our stromas:
“People with blue eyes have a completely colourless stroma with no pigment at all, and it also contains no excess collagen deposits. This means that all the light that enters it is scattered back into the atmosphere and as a result of the Tyndall effect, creates a blue hue. Interestingly, this means that blue eyes don’t actually have a set colour – it all depends on the amount of light available when you look at them.”
And according to the same principles, says Stroma Medical chairman, Gregg Homer, under every brown eye is a blue eye. “If you take that pigment away, then the light can enter the stroma – the little fibers that look like bicycle spokes in a light eye – and when the light scatters, it only reflects back the shortest wavelengths and that’s the blue end of the spectrum,” he told Susie Poppick at Time Magazine. Via You can now turn your brown eyes blue for $5,000