"There is currently no scientific evidence that supports the existence of the sanpaku eyes phenomenon. There is also no evidence to suggest that many of the listed conditions, such as the overconsumption of grain, are related to sclera visibility.[original research?] Additionally, searching the term “sanpaku” does not yield any results in any mainstream psychological or medical journals.[original research?]
The populariser of the sanpaku eyes phenomenon, George Ohsawa, did not have any training in the medical field, and is thus not qualified[original research?] to make diagnoses or medically related predictions. In a similar vein, Ohsawa also does not provide any explanations for the supposed links between particular physical ailments, mental disorders, personality types and the different types of sanpaku (e.g.: why exactly is a visible upper sclera indicative of psychosis?[original research?]). Ohsawa also makes note of some famous people with sanpaku eyes, such as Marilyn Monroe, James Dean, Martin Luther King Jr., Abraham Lincoln, and John F. Kennedy, and insinuates that their demise was linked to the visible sclera under their eyes.[3]
However, there is no mention of people (both famous and non-famous) with this characteristic that do not adhere to the list of symptoms.[original research?] Making observations on famous people exclusively results in a biased and non-random sample, from which results or observations cannot be generalized.[original research?] It is highly likely that many (if not most) people with sanpaku live healthy and normal lives.[original research?]
In order to test this phenomenon, a scientific approach would be to acquire a random sample, whose sclera visibility would be compared to their medical history.[original research?]"
http://self.gutenberg.org/articles/sanpaku