Re: Why do my eyes change colors based on my current mood?

Hi Daniel:

     Although I am not aware of any research in this area and have not 
read anything scientific about this, I will offer you my own theories as 
to why your eye colors may seem to change.  My guess is that you have 
rather light eyes, either blue, green, or a mixture of both.  It is true 
that some people's eye color can appear to change but I am not sure how 
much change can be elicited.  My theory is that the iris ( the colored 
part of the eye that gives it its color), behaves in much the same way as 
a person's face does, especially a face with pale or light complexion.  I 
am sure you have heard people commenting on another's face as being 
"really red".  Well, there is a physiological explanation for this.  The 
capillaries in the skin of the face become dilated, thus the percieved 
"redness".  It makes sense that the more blood in your facial skin, the 
more "red" it would appear.  As you know, the skin is semi-translucent, 
meaning some light can pass through it.  Just look at your hand and you'll 
see outlines of "blue" veins.  
     I am certain the capillaries of the iris works in much the same way.  
More blood in the iris capillaries will give its color a different 
appearance but exactly what color change, I am not sure.  But it 
definitely is easier to tell when you have a relatively light colored 
iris.  As you may already know, iris color is dependent on the amount of 
pigment in the epithelial cells of the iris rather then a difference in 
color.  More pigment = dark or brown irides and less pigment = light or 
blue irides.  
     Now back to the question of when your eyes color changes.  Well, as 
you know, people's faces tend to get redder when they are mad or 
embarrassed, so it can be assumed that under these emotional situations, 
iris color may appear to deviate from its "normal" color.
     I hope the above has helped.  I would offer a reference for this 
topic but I do not know where one exists!  Anyway, good luck!

Kenton L. McWilliams, O.D.