Eye Color

H E T E R O C H R O M I A by Bill_Lloyd_MD, on 5/4/2005 12:16:15 AM Welcome to our WebMD community. There are a wide variety of iris colors (tan, gray, green, blue, brown), but all of them rely on the brown pigment MELANIN for their color. How can that be? The iris tissue is home to a special cell called the MELANOCYTE. These cells produce and release melanin granules. On average, all humans have the same number of melanocytes, but we differ in the amount of melanin produced. Next we need to consider the Tindall effect. Look at the underside of your wrist. Do you see the prominent blue veins? But wait! You and I know the blood inside those veins is deep RED, not blue. If you don't believe this you'll just have to trust me...I'm a doctor. Venous blood APPEARS blue because of the Tindall effect. When visible light strikes your skin the melanin absorbs certain colors, transmits other colors, and reflects what's left over. The BLUE represents reflected visible light due to the Tindall effect. Now, back to the eyeball. The melanin in the iris has a similar effect. If there is lots of pigment granules the iris will appear dark brown. As the amount lessens, so will the color intensity. Brown – Hazel – Green – Blue – Grey – Pink (albinos...no pigment!) When the color of the iris changes (in part or totally) we call that HETEROCHROMIA. Heterochromia can be congenital or acquired later in life. Most causes have no genetic predisposition. Causes include faulty development, inflammation, hemorrhage, foreign bodies, medications, or excess pigment production. One more thing, an infant's eye color will change (darken) over the first 3-6 months of life. Adults who take the glaucoma eyedrop Xalatan (Latanaprost) may also experience darkening of eye color. WebMD hopes you have found this information useful. Come visit us often. WebMD

Thanks to Linda for the tip of searching WebMD. This wasn't up on the blog for two hours before someone had the right idea. I feel much better now.
Check out this poor schmuck (just kidding).

by neenuvar, on 5/26/2005 7:26:57 PM I have a question about my eye color. For the longest time I don't know what to put as my eye color on ID applications. When I was younger my eyes were always blue. I was the only one in the family to have blue eyes that anyone knew of. I know eyes change color after puberty, but mine always change color. Throughout the day my eyes can change from a series of different colors. It will be blue one minute, then green, then purple. I only noticed when people have approached me and complimented me on my eye color, of which was different each time. I noticed that sometimes they will change according to wardrobe or mood. Usually blue when I'm sad, green when I'm happy and then sometimes a mix. The thing is that its not a greenish blue, its either very blue or very green or very other colors. Its has never gotten to brown yet. For a week now it has settled into a mixed array of colors, one eye is mostly blue and green and the other is green, blue, purple and a few other colors. My friends think its awesome but I want to know if there is a reason for this, or its just a random occurrence. Thank you. WebMD