Predicting a baby’s eye color is a bit more complicated than determining which parent has a blue eye gene and which has a brown one. Eye color is a fascinating trait influenced by genetics, melanin production, and the migration of eye color cells in the iris. Here’s an overview of how eye color works and why some babies are born with blue eyes that may change over time:
What Is Eye Color? Eye color refers to the color of a person’s iris, and it can vary across a spectrum, including shades like blue, green, brown, hazel, grey, and amber. The iris contains melanin, the pigment responsible for eye color. The amount of melanin and how light interacts with it determine a person’s eye color. People with little to no melanin can have red, pink, or violet eyes, which is a condition known as albinism.
How Is Eye Color Determined? Eye color is determined by the overall amount of melanin produced by melanocytes throughout the body, as well as the amount of brown pigment within the iris. While a simple model suggests that brown eyes are dominant and blue eyes are recessive, predicting eye color can be challenging due to factors like ethnicity and other hereditary variations. In reality, a baby’s eye color depends on the unique combination of genetics and melanin.
What Color Eyes Are Babies Born With? Most babies are born with their lifelong eye color, although some may be born with blue eyes that change over time. This change in color occurs because eye color cells, derived from neural crest cells, migrate into the iris late in gestation and postnatally. This migration process takes about six to nine months and is influenced by the sympathetic nervous system. So, babies are not born with blue eyes and then change; instead, it takes some time for their eye color to fully manifest.
When Does Baby’s Eye Color Change—If It Changes at All? Around 10 to 20% of babies experience a change in eye color. If your baby is born with blue eyes, but you and your partner have brown eyes, there’s a good chance that your baby’s eyes will gradually change to their lifelong color within the first six months of life. The migration of eye color cells plays a significant role in this process.
Is There Any Way to Predict Baby’s Eye Color? While it can be fun to try and predict your baby’s eye color based on your and your partner’s eye colors, it’s not always accurate. The Mendelian genetics model provides some general guidelines, but eye color is influenced by various factors, making predictions challenging.
In summary, predicting a baby’s eye color involves complex genetics and melanin production. While some babies are born with blue eyes that change over time, most babies are born with their lifelong eye color. If you have concerns about your baby’s eye health or any unusual eye color changes, it’s advisable to consult with an ophthalmologist.