Changing eye color

Under normal physiological conditions, exactly what might cause gradual changes in eye color beyond adolescence is not known. Presumably, environmental and/or genetic factors might interact with the cells in the iris, causing an increase or decrease in the degradation of melanin within the stromal melanocytes, and perhaps a change in the number and/or size of these melanocytes. It is possible that stress may impact this process, but there is no evidence to support that claim per se. I came across one interesting observation that may be relevant here. A medication called latanoprost causes an increase in iris pigment in some patients. This drug is a prostaglandin analogue, which means that it mimics this particular hormone in the body. Exactly how it does this isn't clear. But, this may provide some evidence that various hormones in the body can alter iridial pigmentation over time.

An interesting side note here is the observation that many infants have eyes that appear blue at birth, but which later change color. This change primarily reflects an initial delay in melanin production within the iris stromal melanocytes, with full pigmentation achieved by around three years after birth.

I should also mention that there are a few diseases that are known to result in a progressive loss of iris color (Horner's syndrome and Fuchs' heterochromic iridocyclitis are two examples). I share this information only as a point of interest and it is by no means a diagnosis. (I am not a physician so please seek professional advice if you suspect that you have a medical problem.)



http://www.madsci.org/posts/archives/nov2000/974095954.Ge.r.html"
What can cause a change in eye color during adolescence?