National Different Coloured Eyes Day on July 12 is all about heterochromia iridum. If you’ve ever met someone who has multicolored eyes, or two eyes of a different color, you’ve encountered someone with the absolutely stunning trait known as Heterochromia. It’s not just humans either, it exists in dogs and cats as well, and it is far and away one of the most beautiful, stunning, and mysterious physical traits mankind is known to possess.
There are actually three different kinds of heterochromia iridum – complete, segmental, and central. Central, the most common, appears as matching irises with different colors encircling the pupils. Many don’t know this classifies as heterochromia iridum! Segmental heterochromia appears as a different patch of color in only one iris, and complete heterochromia is the most iconic – two irises of different colours.