Baby Eye Color Calculator

Which Genes Will Your Baby Inherit?

Eye color is a physical trait determined by the pairing of genes from both the parents (1). Each parent contributes 50% of the genetic material that determines eye color. Genes mutate to give alternative forms called alleles, and each allele slightly differs from the other (2). As per the most widely stated eye color genetics, Mendelian genetics, there are three pairs of alleles responsible for eye color with each allele giving either brown, green, or blue. The brown allele is dominant over green and blue; green is dominant over blue and blue is recessive, meaning least dominant.

The characteristic of the dominant allele is what is expressed. Whereas, the characteristic of recessive alleles is expressed only in the absence of a dominant allele. As per this model, the newborn’s eye color depends on both the parents’ eye color and whether the alleles are dominant or recessive. The child may get two dominant alleles from the parents, one dominant one recessive or two recessive alleles (3). In that case:

• The child will have brown eyes if it receives a recessive allele (blue) from one parent and a dominant allele (brown) from the other parent.
• Baby blue eyes depend on whether or not they receive blue alleles from both parents. Since blue is recessive and there is no dominant allele, the child will have blue eyes.
• The child will have green eyes if it receives green alleles from both the parents or one green and one blue allele.

What Determines Eye Color?

When it comes to eye color, we often use the letters B and b to represent the versions of the gene (alleles) involved. B stands for the dominant trait, which is brown eye color, and b stands for the recessive trait, which is blue eye color. As per Mendelian genetics, eye color is decided by the following factors (3):

• Homozygous And Heterozygous
  Human beings have two copies of every gene. One is inherited from the mother, and the other from the father (4). These two copies can either be the same or different, and that’s where the terms homozygous and heterozygous come in. Homozygous means that the two copies of the gene are the same ( BB or bb) and heterozygous means that the two copies of the gene are different (denoted by Bb) (5).
• Dominant Eye Color
  Brown and green are dominant eye colors. There is a 75 to 95% chance of the baby getting brown or green eyes if both parents have the same colored eyes.
• Recessive Eye Color
  Blue is a recessive eye color. It’s highly unlikely for a baby to have blue eyes if both the parents have brown eyes.
• Genotype
  The genotype is the specific allele combination for a given gene, which, in this case, is for the gene for eye color (6). The mother and father’s genotype will determine the eye color of the children.
• Phenotype
  The phenotype is the physical appearance of the genotype, which in this case is the eye color (6).

Will Your Baby’s Eyes Stay Blue?

Most newborn babies have blue eyes, which may change color over time. The eyes may remain blue if both parents pass their recessive blue genes to the child. If this is not the case, the baby’s eye color changes to a permanent color (brown, green or any other color) as he/she ages. At the time of birth, there is a deficit of melanin pigment, but with time the iris starts producing melanin to give the eyes their actual color. It takes about six months to one year for the baby’s actual eye color to surface (7).

Most babies of Caucasian origin have dark blue eyes when born. However, the original color, be it brown, green, blue, or hazel, will be determined over time. The child will get the actual eye color with exposure to light, and it depends on the amount and diffractionⁱThe bending and spreading of light waves when they pass through small openings or around obstacles. of light.

Likewise, Asian and African-origin babies have brown or dark gray at the time of birth. They turn black or real brown over time.

• During birth, the infant’s eye color is light, since newborn babies do not have active melanin which darkens the cells.
• Once your baby is 6 months old, the eye color begins to change.
• Gradually, the eye color takes on a different shade as per the genetic inheritance. Such change starts around the age of six months.
• By the age of three, kids have a definite eye color, which does not change further.

Interpretation Of Baby Eye Color

The baby eye color calculator uses the following probabilistic model to estimate the likelihood of a child inheriting a specific eye color.

• If both the parents have blue eyes, there are 99% chances that the baby will have blue eyes.
• If both the parents have brown eyes, there are 75% chances that the baby will have brown eyes.
• If both the parents have green eyes, there are 99% chances that the baby will also have green eyes.
• If both the parents have hazel eyes, there are 99% chances that the baby will also have hazel eyes.
• The hazel eyes are still a mystery. The baby eye color calculator cannot accurately predict the likelihood of your child having hazel eyes, as this eye color is often a mixture of brown, green and amber hues.

While it’s true that children inherit genetic material from both parents that influences their eye color, research suggests that the old idea that it’s a simple dominant/recessive pattern (like brown always dominating over blue) isn’t accurate (3). Eye color actually depends on the amount of melanin in the iris. Think of melanin like natural coloring: the more melanin present, the darker the eyes appear. Several genes work together to control how much melanin is produced and stored in your eyes (8). This explains why eye color can sometimes seem unpredictable – two blue-eyed parents can occasionally have a brown-eyed child, or two brown-eyed parents might have a child with lighter eyes. It’s because multiple genes are involved, not just one, and they can combine in various ways (3). While we can often make educated guesses about what color a baby’s eyes might be based on family history, there’s no guaranteed way to predict it.

While eye color inheritance is more complex than previously understood, modern genetic research provides increasingly accurate insights into how this trait is passed down. Our baby eye color calculator offers evidence-based predictions while acknowledging the limitations of current genetic understanding. For parents, predicting a baby’s eye color can be fun, but it’s not an exact science. Tools like eye color calculators can give you an idea of the possibilities, but the final result is always a beautiful surprise.