Changing eye color is an increasingly popular cosmetic procedure. But what risks does it involve? Are current techniques safe? Dr. Juan Álvarez de Toledo from the medical team at Oftalvist Barcelona sheds light on this important decision for our visual health.
What determines our eye color?
Our eye color depends on the amount and distribution of a pigment called melanin in the iris — a fibromuscular tissue that forms the pupil diaphragm. There are two types of melanin: eumelanin (dark brown) and pheomelanin (reddish-brown). Depending on how much melanin is present in the iris epithelium and stroma, and the density of these tissues, the eye acquires a specific color.
What are the most common eye colors and why?
Globally, brown is the most common eye color, except in Europe, where a variety of colors such as hazel, green, blue, and gray appear. Initially, it was believed this was linked to genes that control skin pigmentation, but there’s no clear connection in most cases.
Some theories attributed this to genetic mixing with Neanderthals, but the limited gene flow doesn’t explain the high incidence of non-brown eyes in Europe. Other geneticists suggest it’s due to sexual selection: when one sex outnumbers the other, individuals compete for mates using traits like bright or unusual eye colors to attract attention.
Can we change our eye color?
Many people have a cosmetic desire to change their eye color, but achieving it is not simple. There are both reversible and irreversible techniques.
The simplest and most reversible method is cosmetic contact lenses, available in many colors. They provide excellent cosmetic results but must be used carefully to avoid complications such as conjunctivitis or serious corneal infections.
Among permanent solutions, there are surgical methods like keratopigmentation, or corneal tattooing. This involves creating a small circular pocket inside the cornea with a femtosecond laser and filling it with colored pigments, producing a convincing cosmetic effect.
Keratopigmentation is also used therapeutically in pathological eyes to correct iris defects.
Another technique involves iris depigmentation using a special laser that removes melanin and lightens the iris color. Artificial irises were also designed and implanted in front of the natural iris, but most cases had disastrous outcomes.
Are these techniques safe? What are the risks?
Laser depigmentation carries the highest risk. The laser releases pigment into the eye’s aqueous humor, which can clog the drainage meshwork and raise intraocular pressure, potentially causing glaucoma. If uncontrolled, this can lead to irreversible optic nerve damage and vision loss.
Keratopigmentation, being performed on the cornea, may cause minor changes in vision, affect night or peripheral vision, and complicate future intraocular surgeries. Long-term pigment tolerance and degradation are also important concerns. Though less aggressive, it still carries potential risks.
What is the ophthalmology community’s opinion?
Most ophthalmologists oppose elective eye color change surgery on healthy eyes due to the unacceptable risks. Laser depigmentation and artificial iris implants have been largely abandoned due to their serious complications.
In contrast, cosmetic keratopigmentation is being performed in a few international centers. However, the lack of long-term, peer-reviewed studies in prestigious ophthalmology journals — despite some positive conclusions — prevents widespread acceptance.
On the other hand, keratopigmentation for pathological cases is considered fully justified when it solves issues that impair a patient’s visual quality, such as partial or total loss of the iris.
As for cosmetic keratopigmentation, since it remains rare and controversial, caution is advised. Long-term results are needed to determine whether the procedure is truly safe and what complication rates exist, so that patients can be properly informed.
Medical article by Dr. Juan Álvarez de Toledo
