Yes, red eyes exist, but not in the way one might initially think. True red pigmentation in the iris is extremely rare. The appearance of red eyes is typically due to a lack of melanin, the pigment responsible for eye color, allowing the blood vessels within the iris to show through.
Causes of Red Eyes
-
Albinism: This genetic condition results in a significant reduction or absence of melanin in the eyes, skin, and hair. The lack of melanin makes the blood vessels highly visible, giving the eyes a reddish or pinkish appearance. [Sources: Cleveland Clinic, Quora, All About Vision, Warby Parker, eyeXam Optometry]
-
Blood Vessel Leakage: In some cases, blood leaking into the iris can also cause redness. [Source: eyeXam Optometry]
It's important to note that the "redness" is often described as pinkish. The color is not a true, vibrant red, but rather the color of the blood vessels beneath the surface of the iris. [Source: Eye Doctors of Washington]
Differentiating Red Eyes from Other Eye Colors
It's crucial to distinguish the reddish appearance resulting from a lack of melanin from other eye colors. The lack of melanin in albinism leads to the visibility of underlying blood vessels, resulting in a pink or reddish hue, not a true red pigment within the eye itself. This is different from other colors like brown, blue, green, or hazel, which are the result of varying concentrations of melanin. [Source: Wikipedia]
