Sanpaku eyes are going viral — again — and the internet can’t stop diagnosing people because of them. The eye trait, which shows extra white either above or below the iris, has sparked everything from TikTok explainers to armchair psychoanalysis. But what do sanpaku eyes actually mean, and why are people so fixated on them?
The term “sanpaku eyes” comes from Japanese and translates to “three whites,” referring to when more of the sclera (the white part of the eye) is visible than usual. In Western medicine, the same feature is called “scleral show,” and it’s typically considered a neutral physical trait. It can be inherited, appear with aging, result from injury or illness, or even occur after cosmetic procedures like blepharoplasty.
What Are Sanpaku Eyes, Exactly?
Most people see their iris centered, with white visible only on either side. Sanpaku eyes describe cases where white shows either below the iris (called yin sanpaku) or, more rarely, above it (yang sanpaku). The concept originates in Japanese face reading, a form of physiognomy — the practice of assigning personality traits based on physical features.
That’s where the mythology kicks in. Traditionally, yin sanpaku was believed to signal inner imbalance or physical turmoil, while yang sanpaku was associated with aggression or emotional volatility. But experts stress these interpretations are rooted in superstition, not science.
Are Sanpaku Eyes Rare?
Not at all. Research measuring eyelid position in healthy individuals found that nearly half showed some degree of visible white below the iris, averaging about 0.4 millimeters. The amount varies depending on anatomy, including how far the eyes sit forward in the socket. In other words, sanpaku eyes are simply one of many normal variations in eye shape.
Why the Internet Keeps Fixating on Them
Celebrities often get pulled into the conversation. “Singer Billie Eilish, Diana Ross, Marilyn Monroe, James Dean, Twiggie, Princess Diana and President John F. Kennedy all have or had this trait,” body language expert Patti Wood, author of Snap: Making the Most of First Impressions, Body Language and Charisma, told First for Women in 2023. She adds that while sanpaku is a mystical tradition, science points to genetics and health factors, including thyroid conditions.
Still, yang sanpaku — white above the iris — tends to fuel darker internet theories, especially when paired with infamous figures like Charles Manson. Some online sleuths have even claimed murder suspects have “sanpaku eyes,” reinforcing the idea that eyes reveal hidden danger.
The Science Behind “Eye Reading”
“Long before we had the science of body language, people were already ‘seeing things’ in the eyes,” says Wood. “That’s because eyes are the first part of the body we look at — they’re a key indicator of one’s emotional state and can signal the next action a person may take by what they’re looking at or focusing on.”
Research supports that instinct. Studies from Cardiff University show people can judge traits like compassion or competence within milliseconds, according to retired FBI profiler Joe Navarro, author of Be Exceptional, per First for Women.
“The whites of the eyes are the first thing I notice when I look at police photos or a ‘perp walk,’” Wood explains. The unnerving, wide-eyed glare seen in some criminals triggers our fight-or-flight response, a reaction Navarro calls “reptilian indifference.” “Many psychologists… talk about the fact that when they’re in the presence of a true psychopath, they react viscerally to the coldness of their stare,” he says.
Thankfully, true psychopaths make up only about 1% of the population. The real takeaway? As Navarro puts it: “Trust your gut.” Whether sanpaku or not, your instincts matter more than an internet diagnosis.
