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Your eye color is determined by the actions of genes that regulate the deposition of the melanin pigment in the iris of your eyes.  If your eyes are blue, that means there is no pigment present in them. Actually, there is no blue pigment. The blue hue in your eyes is just a reflection. It’s just like when you look at the sky and the reflected color that you see is blue.

In the case of green or gray eyes, these colors are determined by the amount of yellow or black pigment stored in the iris which is combined with the blue reflection. If pigment is deposited in high quantity, brown eyes will be produced  which ultimately covers the blue reflection.

In the rare eye color instances, the brown color gets so dark that it will look black.

The main determining factors that constitute the outcome of the eyes’ color are both the pigment-expressing and non pigment-expressing genes. In terms of dominance, pigment genes are dominant; no-pigment genes (“blue” eyes) are recessive.

For easier understanding about how to create your family’s eye color genetics chart, follow this step:

“Reduce the information to “dominant” or “recessive”: pigmented eyes or blue eyes. For example: Grandma: pigmented; Grandpa: pigmented. Mom: pigmented; Dad: blue. Sister: pigmented; Brother: blue.”

Male and female family members should be represented differently in your eyecolor genetics chart. For example: Males- squares; females- circles. Also, assign different colors to dominant and recessive traits. For example: dominant- black; recessive- white. Read the following example on how to do this.

“Grandma who has brown eyes is represented as a black circle. Brother, on the other hand, who has blue eyes is represented with a white square. Uncle who has green eyes is represented with a green square while grandpa who has gray eyes was represented with a red square.”

Now you must arrange all the shapes according to genealogical order. The oldest generation must be on top and the youngest/present is at the bottom.

Husband and wife should be connected by a horizontal line to represent marriage. Children should be connected to the parents through vertical line from the midline of the horizontal line that connects them (mom and dad). See the following example:

“Grandpa’s square and grandma’s circle is connected by horizontal line. In the middle of that line is the vertical line downward to mom’s circle. Mom’s circle is the connected to dad’s square. From the line that connects them appears a line which looks like an inverted T. From opposite arms of the inverted T are vertical lines downward that connect each to my circle and my brother’s square.”

Next thing to do is to analyze your chart. Try to figure out what genes each family member has. Remember the following tip to avoid confusion:

“Genes come in partners called alleles, each one of the pair coming from each parent. Look at the recessives first. Blue eyes means the person has alleles that are both recessive. Since they received one gene from each parent, each of their parents has at least one recessive gene. They must pass recessive genes on to their children, so each of their children has at least one recessive gene.”

Those with pigmented eyes signify that they contain the dominant genes. They may have two dominant genes or one dominant and one recessive. In the case of the latter (called heterozygous dominant) the dominant gene (pigment gene) will be expressed covering the expression of the recessive gene (non pigment gene. That’s why it is not always possible to determine what genes a dominant-trait person has. It could only be determined through genetic analysis.