Babies' eye color typically starts to change between 3 to 9 months of age, most often around 6 months. This change happens as melanocytes in the iris produce more pigment in response to light exposure after birth. While the most noticeable changes usually occur in the first year, the eye color can continue to darken or shift subtly up until about three years old, and in some cases even later. The initial blue or gray color seen at birth is due to low melanin levels, and exposure to light triggers melanin production, which deepens or changes the eye color. Final eye color is usually set within the first few years but may rarely change later in life due to medical reasons requiring attention.
