The term “Sanpaku” is a Japanese word that translates literally to “three whites.” It describes a specific appearance where the white part of the eye (the sclera) is visible on three sides of the iris, instead of the typical two (left and right). This distinct visual feature has historically been interpreted as a sign indicating an individual’s physical or spiritual state.
What Defines Sanpaku Eyes
Sanpaku eyes are defined by the amount of sclera visible around the iris. In most individuals, the upper and lower eyelids lightly touch the top and bottom edges of the iris when looking straight ahead. With Sanpaku, a noticeable strip of white is visible either below or above the iris.
Tradition distinguishes two types based on the location of the visible sclera. Yin Sanpaku (Sambu-Yin) is the more common presentation, where the white space is visible beneath the iris. Yang Sanpaku (Sambu-Yang) is less common, characterized by the sclera being visible above the iris. This distinction is purely anatomical, describing the positioning of the eyelid margin relative to the iris.
The Philosophical and Traditional Meanings
The concept of Sanpaku originated in traditional Japanese and Chinese face reading, known as physiognomy. This ancient practice held that physical features could reveal a person’s character, health, and destiny. The visibility of the sclera was interpreted as a sign that the individual’s system was out of harmony with the universe.
The Yin Sanpaku (white below the iris) was traditionally associated with physical instability and vulnerability. People with this appearance were thought to be prone to accidents, illness, or internal distress caused by an imbalance in diet or lifestyle. The concept gained Western recognition after World War II through macrobiotic philosopher George Ohsawa, who linked the condition to poor health and an “early and tragic end.”
Conversely, the Yang Sanpaku, with the white showing above the iris, was given a much more serious interpretation. This presentation was often linked to mental instability, aggression, and the potential for violence directed outward toward others. Both forms were seen as representing a profound disequilibrium, suggesting the individual was dangerously out of balance, whether physically or mentally. These traditional interpretations became a form of cultural folklore, assigning prophetic meaning to a simple biological trait.
Scleral Show: The Medical Explanation
In modern medicine, the appearance described as Sanpaku is known by the neutral term “scleral show.” This refers to the observation of the sclera between the eyelid margin and the edge of the iris. Scleral show is an anatomical finding attributed to several non-mystical causes.
The most frequent cause is simple genetic variation, as the shape of the orbit and the laxity of the eyelids differ naturally among people. Research has shown that a measurable degree of lower scleral show is present in approximately half of the healthy population, often measuring around 0.4 millimeters. The aging process also contributes to this appearance as the skin and connective tissues surrounding the eye lose elasticity, causing the lower eyelid to sag slightly.
Scleral show can also be a symptom of an underlying medical condition. Thyroid eye disease, such as Graves’ disease, can cause the tissues behind the eye to swell, pushing the eyeball forward and creating a pronounced scleral show. Other causes include complications from cosmetic eyelid surgery (blepharoplasty) or specific anatomical features, like myopia. The visual feature is a consequence of anatomy, tissue health, or physical structure.
The Verdict: Separating Belief from Biology
Sanpaku eyes are undeniably real as a physical, observable trait, medically recognized as scleral show. The appearance is a documented anatomical variation caused by genetics, aging, or sometimes an underlying medical issue. It is not, however, supported by scientific evidence that this visual feature predicts a person’s fate, character, or predisposition to violence.
The traditional meanings are rooted in physiognomy and macrobiotic theory, which lack validation from modern biology, psychology, or epidemiology. No scientific study has established a correlation between the visible white of the eye and an individual’s destiny or personality traits. While the appearance itself is a tangible reality, the associated cultural predictions are best understood as historical superstition or folklore.