Many babies are born with blue or grayish eyes, leading to questions about how common this initial eye color is and if it will change. Eye color often changes significantly during early life.
How Many Babies Are Born with Blue Eyes?
While it is a common belief that most infants are born with blue eyes, this is actually a misconception. Research indicates that a substantial number of newborns are born with brown eyes. For instance, a 2016 study, known as the Newborn Eye Screen Test (NEST), examined a diverse group of 192 newborns and found that approximately 20.8% were born with blue eyes.
In contrast, the same study revealed that a significantly higher percentage, around 63%, of infants were born with brown eyes. This initial distribution varies by heritage; light-skinned newborns often have blue or gray eyes at birth, while those with darker skin are more frequently born with brown eyes.
The Science Behind Changing Eye Color
The color of a baby’s eyes at birth, and its subsequent change, is primarily determined by the amount and distribution of melanin within the iris. Melanin is a pigment produced by specialized cells called melanocytes, which also influence skin and hair color. At birth, babies often have very little melanin in their irises because they have been in the dark environment of the womb, limiting light exposure that stimulates melanin production.
The limited melanin at birth causes light to scatter when it enters the iris, making the eyes appear blue or gray. As an infant is exposed to light after birth, the melanocytes in the iris become more active and begin to produce more melanin. This gradual accumulation of pigment can lead to a darkening of eye color over the first few months or even up to several years.
The amount of melanin ultimately determines the eye’s final shade. A small amount of melanin results in blue eyes, a slightly greater amount leads to green or hazel, and a high concentration creates brown eyes. Brown is the only pigment in the eye; perceived colors like blue, green, or hazel result from varying amounts of this brown pigment and how light interacts with it. Genetics significantly influence a baby’s potential eye color by determining melanin production.