Are there very few people with pure black eyes?

Generally speaking, the color of the eyes refers to the color of the iris, that is, the colored black eyes around the pupil. Although it is said that patients have yellow skin, black hair and black eyes, if you look closely, you will find that most of China people's eyes are not pure black, but dark brown.

Because the brown eye gene is very dominant, about half of human beings have dark brown eyes. True black eyes are much less than blue-green eyes, and the rarity index is five stars. The night is as deep, and the iris is even as black as the pupil. It is generally believed that Costa Ricans in Central America are a small group with black irises. Official website of the Ministry of Foreign Affairs shows that Costa Rica has a population of less than 50,000, accounting for .65% of the world population.