.calc-title { font-size: 28px; font-weight: 700; color: #2c3e50; margin-bottom: 10px; text-align: center; }
.calc-subtitle { font-size: 16px; color: #7f8c8d; text-align: center; margin-bottom: 30px; }
.input-group { margin-bottom: 20px; }
.input-label { display: block; font-weight: 600; margin-bottom: 8px; color: #444; }
.select-field { width: 100%; padding: 12px; border: 2px solid #ddd; border-radius: 8px; font-size: 16px; transition: border-color 0.3s; background-color: #f9f9f9; cursor: pointer; }
.select-field:focus { border-color: #3498db; outline: none; }
.calc-button { width: 100%; background-color: #3498db; color: white; border: none; padding: 15px; border-radius: 8px; font-size: 18px; font-weight: 600; cursor: pointer; transition: background-color 0.3s; margin-top: 10px; }
.calc-button:hover { background-color: #2980b9; }
#eye-results-box { margin-top: 30px; display: none; padding: 20px; border-radius: 10px; background-color: #f0f7ff; border: 1px solid #d1e9ff; }
.result-item { display: flex; align-items: center; margin-bottom: 15px; }
.color-dot { width: 20px; height: 20px; border-radius: 50%; margin-right: 15px; border: 1px solid rgba(0,0,0,0.1); }
.bar-container { flex-grow: 1; background-color: #e0e0e0; height: 12px; border-radius: 6px; overflow: hidden; }
.bar-fill { height: 100%; width: 0%; transition: width 1s ease-in-out; }
.percentage-text { min-width: 50px; text-align: right; font-weight: 700; margin-left: 15px; }
.article-section { margin-top: 40px; border-top: 1px solid #eee; padding-top: 30px; }
.article-section h2 { color: #2c3e50; font-size: 24px; margin-bottom: 15px; }
.article-section p { margin-bottom: 15px; font-size: 16px; color: #555; }
.example-card { background: #f8f9fa; padding: 15px; border-left: 4px solid #3498db; margin: 20px 0; border-radius: 0 4px 4px 0; }
Predict the probability of your baby's eye color based on genetic inheritance patterns.
Understanding Eye Color Genetics
Eye color is a polygenic trait, meaning it is determined by multiple genes. For many years, it was believed that eye color was a simple Mendelian trait (brown being dominant over blue). While that model provides a good baseline, modern science shows that at least 16 different genes play a role in determining the final hue of a person's iris.
The primary genes involved are OCA2 and HERC2, both located on chromosome 15. These genes regulate the production and distribution of melanin. Brown eyes have a high concentration of melanin, while blue eyes have very little.
How the Eye Colour Calculator Works
This tool uses the standard genetic probability matrix based on the three most common eye colors: brown, blue, and green. By selecting the phenotypes (physical appearance) of both parents, the calculator determines the statistical likelihood of their offspring inheriting specific traits.
Example Inheritance: If both parents have Blue eyes, the probability of the child having blue eyes is approximately 99%. However, there is still a roughly 1% chance the child could have green eyes due to the complex interaction of underlying modifier genes.
Common Inheritance Patterns
While exceptions occur, here are the general rules used in our genetic probability model:
- Brown + Brown: There is a 75% chance of brown eyes, an 18.75% chance of green, and a 6.25% chance of blue. This happens because both parents may carry "hidden" recessive genes for blue or green.
- Blue + Blue: Since blue is a recessive trait, two blue-eyed parents almost always have blue-eyed children. It is very rare (though not impossible) for them to have a brown-eyed child.
- Green + Green: This combination results in a high probability of green eyes (75%) or blue eyes (25%), with brown being extremely rare.
Factors That Can Change Eye Color
It is important to note that many babies are born with light blue or grey eyes that darken over the first three years of life as melanin develops. Furthermore, conditions like heterochromia (two different colored eyes) or sectoral heterochromia (different colors within the same eye) are results of unique genetic mutations or developmental factors not covered by standard probability charts.
function calculateEyeColor() {
var p1 = document.getElementById("parentOne").value;
var p2 = document.getElementById("parentTwo").value;
var resultsBox = document.getElementById("eye-results-box");
var brown = 0;
var green = 0;
var blue = 0;
// Genetic Logic Matrix
if (p1 === "blue" && p2 === "blue") {
blue = 99; green = 1; brown = 0;
} else if ((p1 === "blue" && p2 === "green") || (p1 === "green" && p2 === "blue")) {
blue = 50; green = 50; brown = 0;
} else if ((p1 === "blue" && p2 === "brown") || (p1 === "brown" && p2 === "blue")) {
brown = 50; blue = 50; green = 0;
} else if (p1 === "green" && p2 === "green") {
green = 75; blue = 25; brown = 0;
} else if ((p1 === "green" && p2 === "brown") || (p1 === "brown" && p2 === "green")) {
brown = 50; green = 37.5; blue = 12.5;
} else if (p1 === "brown" && p2 === "brown") {
brown = 75; green = 18.75; blue = 6.25;
}
// Display Results
resultsBox.style.display = "block";
var barBrown = document.getElementById("bar-brown");
var barGreen = document.getElementById("bar-green");
var barBlue = document.getElementById("bar-blue");
var textBrown = document.getElementById("text-brown");
var textGreen = document.getElementById("text-green");
var textBlue = document.getElementById("text-blue");
// Update Text
textBrown.innerHTML = brown.toFixed(1) + "%";
textGreen.innerHTML = green.toFixed(1) + "%";
textBlue.innerHTML = blue.toFixed(1) + "%";
// Update Bars with timeout for animation effect
setTimeout(function() {
barBrown.style.width = brown + "%";
barGreen.style.width = green + "%";
barBlue.style.width = blue + "%";
}, 10);
// Scroll to results on mobile
resultsBox.scrollIntoView({ behavior: 'smooth', block: 'nearest' });
}