Although having brown eyes is a beautiful thing, there are a few disadvantages that come with having this dark phenotype. For example, according to an article published in The Journal of Pain, women with brown eyes are more sensitive to pain than their light-eyed (green, blue, gray) counterparts. It seems odd that eye-color would be in any way connected to how well a person can tolerate pain, but science indeed confirms that it is.
So how exactly did the researchers come to this conclusion? They surveyed 58 women at a hospital, all of them expectant mothers, and all who were planning to give birth there. They divided them into two groups: 34 in the group with light-colored eyes, and 24 in the group with dark-colored eyes. Their objective was to monitor postpartum and antepartum pain, sleep, coping behavior, and mood.
After the researchers finished the study, they concluded that women with light eyes had an easier time during labor and delivery than women with dark eyes. Additionally, light-eyed women turned out to be less susceptible to anxiety and depression. Fascinating!