In the classic 1930s movie, "The Wizard of Oz," Dorothy asks the good citizens of Oz whether they could dye her eyes to match her gown, and they happily oblige. Of course, eyes are not like hair, and 75 years on you still cannot dye your eyes to suit your outfit. But it turns out that you can actually change their color with the aid of a laser.
The technique was pioneered by California-based Stroma Medical and it is currently available in several countries, but it has yet to receive approval in the United States. So far, 37 patients in Mexico and Costa Rica have undergone the procedure, which permanently turned their eyes from brown to blue. If you fancy twinkling blue eyes yourself, you had best start saving your pennies as the procedure will set you back around $5,000 (£3,300). Those who don’t fancy breaking the bank are probably happy enough using colored contact lenses.
So how does it work? It actually doesn’t involve adding any color to the eye—blue eyes are not this shade because of blue pigments, but rather the scattering of light. In blue-eyed people, when multicolored light falls on the eye, it is mostly the blue wavelengths that are reflected back and picked up by our own eyes.
The difference with brown-eyed individuals is that the front layer of their eyes, called the stroma, contains an abundance of melanin, the pigment that also gives skin and hair their color. This results in the majority of light hitting the eye being absorbed, but the small amount reflected makes them appear brown to us. So to go from brown to blue, all you need to do is remove the melanin present in the iris.
Stroma Medical’s chairman Dr. Gregg Homer explained to CNN how it works: “The fundamental principle is that under every brown eye is a blue eye. The only difference between a brown eye and a blue eye is this very thin layer of pigment on the surface.
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.”
According to Homer, the laser procedure takes just 20 seconds, although the results won’t be apparent for several weeks as it takes time for the body to remove the dead pigment layer. While the go-ahead has not yet been given to perform the technique in the U.S., preliminary studies have suggested that it is safe, but it will take several years for the clinical trials to reach completion.
Experts in the field have raised their eyebrows about its safety, however, with some suggesting that the pigment could cause a blockage in draining channels, which may increase pressure in the eye, ultimately leading to glaucoma if not resolved. But Homer counters this argument by pointing out that the debris resulting from the procedure would be too small to cause such problems.