Understanding the inheritance of eye color has been a challenge for decades. Most parents try to make their best guess about their unborn child’s eye color, hoping for that warm brown or the more rare bright blue outcome.

"Eye Colors in Man," from The Trait Book, ERO Bulletin No. 6, by Charles B. Davenport (Archive Image #1913)

"Eye Colors in Man," from The Trait Book, ERO Bulletin No. 6, by Charles B. Davenport, 1912 (Archive Image #1913)

Davenport and other eugenicists oversimplified eye-color inheritance early in the last century, and we have since come to discover that several genes determine eye color.

 

Recently, a group in the Netherlands has taken our understanding a step further by using high resolution imaging and analysis of nearly 6,000 individuals to identify eye-color using a color spectrum, while previous studies utilized color categories (blue, green, brown). The researchers photographed the subjects’ eyes and identified the color on a spectrum that evaluated hue and saturation. Then they conducted a genome-wide association study and found three new regions on chromosomes 1, 17, and 21 that contribute to eye-color-variation, adding to the seven already known genes. They claim that using their prediction model, 50% of eye-color variation can now be explained. Davenport wouldn’t believe his eyes!

Read more about the study here: http://blogs.nature.com/news/thegreatbeyond/2010/05/suspect_has_hazel_eyes_with_h.html