People With Blue Eyes Have A Higher Alcohol Tolerance

Eye color is a polygenetic, partially sex-linked trait, meaning that it is controlled by multiple genes, one of which is located on the X-chromosome. 

The color of the eyes is determined not by different pigments but by the number and size of melanin particles in the layers of the iris. More melanin makes the eyes appear darker, moving from blue to grey, green, hazel, brown, and black.