While researchers are still working to pinpoint a reason for spontaneous haemolacria, there have been a few clues along the way. A 1991 study linked haemolacria to female fertility.
Of the 125 examined subjects (all of whom were in good health), researchers discovered that 18 percent of menstruating women had blood in their tears, compared to 8 percent of men and 7 percent of pregnant women.
