By Jenn Mossholder
I was out running errands with my 10 year old today and she asked a question a lot of new parents ask, "Why are babies born with blue eyes? Why do they change?".
Here is your answer:
Melanin, the brown pigment molecule that colors your skin, hair, and eyes, hadn't been fully deposited in the irises of your newborns's eyes or darkened by exposure to ultraviolet light. (Like sunlight!) Melanin production generally increases during the first year of your baby's life, leading to a deepening of eye color. The color is often stable by about 9 months of age.
Some babies can be born with their eyes already turned brown (blue eyes in the States currently only account for less than 20% of babies born after the 1990's); however, we all start out in the womb with blue eyes.
My husband and I both have very dark brown eyes but our four girls have: light brown eyes, green eyes, bright blue eyes and dark brown eyes. Why the variation? Both of our fathers had blue eyes! (If you remember your Punnett Squares from HS Biology, he and I are "Bb" and not "BB" as we just assumed we'd were.)
According to wikipedia, the breakdown for eye color is classified in the "Martin-Schultz Scale". Green eyes are the rarest to have; about 2% to 3% of Americans have them, whereas Icelandic populations it is as high as 87%! Blue eyes have decreased in frequency as intermarriage among ethnicities has increased over the years and are about 17% in America but occur more frequently in Europe. Brown eyes are the World's most popular eye pigment accounting for over two-thirds of the population.
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