Purple Eyes: A Rare And Captivating Phenomenon
Blue, brown, green, and hazel eyes are common, but purple eyes are a rare and extraordinary sight. People with this unique eye color possess a condition that affects the way light interacts with the pigments in their irises. Our eyes are comprised of a combination of melanin, lipochrome, and pheomelanin which contributes to their color as well as other factors. In this article, we will delve into the science behind purple eyes, explore the specific conditions that cause this rare phenomenon, and examine the various cases of individuals who have been found to possess this unique eye color.
Simonne Naidoo, the South African woman who gained international fame for her striking purple eyes, brought attention to her condition in a 2013 interview. When asked about the constant curiosity surrounding her eye color, Naidoo stated, "I've been getting a lot of attention, especially in the media, for my unique eye color, which is abnormally rare, occurring in less than one percent of the global population." She added, "I never knew my eyes were unusual growing up; it was only after graduating that I was told it's extremely rare."
The Biology of Eye Color
The color of a person's eyes depends on the interaction between the pigments in the iris and light. The amount and distribution of melanin in the iris, directly influences the perceived eye color. In most people, melanin—causing the brown pigment in the eyes—is predominant, but a few organic pigments, such as lipochrome, play a crucial role in the coloration of an individual's eyes. Lipochrome interacts with melanin in the iris and controls the amount of light that enters the eye. This interaction is what produces the characteristic purple hue seen in very few cases.
Purple eyes are characterized by a strong interaction between melanin and lipochrome in the iris, which determines the exact shade of the color. When the interaction between the pigments in the eyes intensifies, purple tone starts to take shape. In rare cases, people with this unique eye color have been found to have no melanin or intermediate levels of melanin, which leads to this described light, astoundingly saturated purple tone.
The Contribution of Lipochrome to Purple Eyes
Hyderabad-based genetics researcher, Dr. Arshi Rizvi, describes lipochrome's role in determining eye color as follows:
"Our research has found that lipochrome and melanin work in tandem to generate a wide range of eye colors. When the interaction between these two pigments is reduced, people are likely to have light brown or amber-colored eyes. On the other hand, with combined yields of melanin, individuals may have blue or green eyes. But when the distribution of lipochrome intensifies, you're left with what we'd describe as a truly unusual, striking purple color."
The interaction of the two main pigments is affected by several key factors, including genetics and disease. Since the genetic makeup of each individual contributes significantly to the pigmentation and formation of the iris's rhodopsin layer, any irregular difference during development could be a determinant in the possibility of one possessing the rare purple hue.
Records of Purple Eyes
Although purple eyes are extremely rare, the phenomenon is documented in medical literature. In one case study, a 49-year-old man from South Yemen was diagnosed with 'Leber's congenital amaurosis', a rare disease linked with both very rare albinism and complete blindness due to progressive vision loss. He experienced extraordinary, sharp vision despite not being able to see without assistance due to disrupted melanin presence in his cells. He developed purple eyes as a result of intermediate melanin levels.
