Tuesday, March 24, 2009
Are You Heterochromia?
A person who has different amounts of melanin in each of the irises has a condition known as Heterochromia iridium, a scientific name for two different color eyes in the same individual. Though relatively rare in humans, it happens when something has gone a bit wrong in making eye color, or if the body happens to shut off a gene in only some cells in the body. According to Dr. Azita Alizadeh of Stanford University, Heterochromia can be the result of too much or too little pigment in the iris of one eye. Less or no pigment gives blue eyes, more pigment gives green, and a lot of pigment gives brown eyes. A person may actually have a different set of eye color genes in each eye. Heterochromia can be attributed to genetics, to disease, or to injury. Some famous people with Heterochromia reportedly are David Bowie, Christopher Walken, Kiefer Sutherland, Dan Aykroyd, Jane Seymour, and Alexander the Great. Carleton Coon created a chart of eye color by the Martin-Schultz scale that includes amber, blue, brown, gray, green, hazel, red and violet. But, the perception of eye color is dependent on viewing conditions (such as the amount and type of illumination and the hue of the surrounding environment) and color is based on a continuum of dark brown shades to light blue shades. Whatever eye color(s) you possess, you must agree the human eye is a true marvel. Here are some nuggets of human eye trivia that may amuse. 1. The eyes are composed of more than 2 million working parts. 2. Babies cry but don't produce tears until one to three months after birth. 3. The older the eyes, the less tears they produce. 4. Of all the muscles in the body, the eye muscles are the most active. 5. 80% of what is learned is learned through the eyes. 6. The cornea is the only living tissue in the body that does not contain any blood vessels. 7. The eyebrows' purpose is to keep sweat from running into the eyes. 8. The eyelashes are home to microscopic creatures that fight off bad bacteria from the outside world.
Posted by Frank Thompson at 1:17 PM