posted on Jan, 31 2008 @ 11:16 PM
reply to post by whitewave
"Pigment in the front layer of the iris (called the stroma) colors the iris. Eye color lightens when pigment granules drop in number, or when the
granules make a lighter color. See figure. The iris can also lose color if the pigment degrades.
Eyes, unlike skin and hair, do not synthesize color pigment continuously. Instead, eyes keep pigment granules made earlier. So, if the pigment
degrades, the eye color lightens.
Likewise, eyes can darken if the number of pigment granules increase or if the granules make darker pigment."
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