Why do all newborn babies have blue eyes?
At birth, the genes that make the pigment protein are not being read by the cell (they are turned off). Almost all babies have blue eyes because the iris has not yet made brown pigment (called melanin) that colors the iris.
As the child’s eyes are exposed to light (as they weren’t in the womb), the light then triggers the cell to start reading the gene. But it can take a while for the cell to ramp up to the final levels of pigment. That is why so many babies have blue eyes for their first months of life. Usually by their first birthday a baby’s eye color has settled in, but sometimes the iris doesn’t make enough melanin until about 3 years of age.
A nice description from About.com follows: “An infant’s eye color is determined by a substance called melanin. Melanin is a dark pigment contained in the iris, the structure that controls how much light is allowed into the eye. The color of the iris is determined by the amount of melanin in the iris. Light eyes have very little pigment, whereas darker eyes have a lot. In newborns, the pigmentation process of the iris is not yet complete. Babies with darker skin are usually born with dark eyes that stay relatively dark. Iris color in lighter-skinned babies is usually a blue or bluish-gray color at birth, then change as they grow. Melanin production changes during the first year of life, usually resulting in a darker, deeper eye color.”
Sources: Understanding Genetics at TheTech.org.
Beg to differ with you – both me and my daughter were born with DARK brown eyes, and I can attest to you that when my daughter was handed to me and opened her eyes not 5 minutes after she was born, they were dark brown.
Thank you so a lot for bringing this all together, you rock person.
The second sentence says “almost” all babies have blue eyes at birth. There are always exceptions. The same logic demands that you can’t say all humans are born with ten fingers either. Since every once in a while someone will be born with nine or 11. But… generally speaking, babies are born with ten fingers. And blue eyes.
i couldn’t have said it any better.
Simply not true, while I do understand that the statement is qualified by “almost” – this simply does not match my experience: My mother had 8 children, all brown eyes. Nieces/nephews/cousins/family friends/my own child…all have brown or black eyes. It is almost unheard of in my culture for a baby to have blue eyes, though it does occur.
Brown- that does seem to go against conventional wisdom. I guess if the question asked was Why are so many babies born with blue eyes? the answer above would be more correct.
Anyway, I hope anyone reading this post will also read your comment and realize that there are some families (and perhaps cultures) who aren’t as prone to have babies born with blue eyes. Thanks for commenting.