Eye color

People's eyes are divided into eight colors: black, blue, green, brown, brown, yellow amber, gray and light purple.

1, black: This is the most. Most people in China have black eyes, and so do Africans.

2, blue: Europeans and Americans

3. Green: Green eyes are more common in northern Europe.

4. Brown: Asians are brown and dark brown.

5. Brown: Asian race

6. Yellow and amber: Asian race

7, gray: Europeans and Americans, etc.

8. Light purple: Purple is rare, and the famous actress Elizabeth Taylor is famous for her purple eyes.

Extended data:

Previously, people thought that eye color was a simple genetic feature, and children's eye color could be predicted according to the eye color of parents and even grandparents. However, geneticists point out that there are as many as 16 different genes that affect the color of our eyes to varying degrees. The anatomical structure of iris also affects the color of eyes to some extent.

Therefore, even if parents have blue eyes, there is no guarantee that children's eyes are blue, even the royal family is no exception. Princess Charlotte, the daughter of Prince William and Kate, has beautiful blue eyes, while her brother Prince George has brown eyes.

In addition, being born with blue eyes doesn't mean being blue eyes all your life. At birth, the amount of pigment in babies' eyes is very small, so many babies are born with blue eyes. But when it reaches infancy, with the development of eyes and the production of iris melanin, the color of eyes will turn green, light brown or brown.

People's Network-The amount of melanin in iris determines the color of our eyes.

Baidu encyclopedia-eyes

How many colors do China's eyes have?

Hello! Our eyes in China are black, so why are the eyes of westerners blue or other colors? In fact, when we say that the eyes are different in color, we actually mean that the middle part in front of the eyeball is different in color and is composed of cornea, iris and pupil.

Because the cornea is colorless and transparent, the color of the eyeball is the color of the iris. The iris of human eye consists of five layers: endothelial cell layer, anterior limiting membrane, matrix layer, posterior limiting membrane and posterior epithelial layer.

Among these five layers of tissues, there are many pigment cells in anterior limiting membrane, stroma layer and posterior epithelial layer, and the amount of pigment contained in pigment cells determines the color of iris. The more pigment contained in pigment cells, the darker the iris and the darker the eyeball. The less pigment contained in pigment cells, the lighter the iris color and the lighter the eyeball color.

The pigment content in pigment cells is consistent with skin color, which is related to the genetic relationship of race. Orientals are colored people, and the iris has a lot of pigment, so the eyes look black. Westerners are white, the iris has a little pigment, and the blood vessels are distributed in the matrix layer, so the eyes look light blue or green.

How many colors do human eyes have?

Our eyes in China are black, so why are the eyes of westerners blue or other colors? In fact, when we say that the eyes are different in color, we actually mean that the middle part in front of the eyeball is different in color and is composed of cornea, iris and pupil. Because the cornea is colorless and transparent, the color of the eyeball is the color of the iris.

The iris of human eye consists of five layers: endothelial cell layer, anterior limiting membrane, matrix layer, posterior limiting membrane and posterior epithelial layer. Among these five layers of tissues, there are many pigment cells in anterior limiting membrane, stroma layer and posterior epithelial layer, and the amount of pigment contained in pigment cells determines the color of iris. The more pigment contained in pigment cells, the darker the iris and the darker the eyeball. The less pigment contained in pigment cells, the lighter the iris color and the lighter the eyeball color. The pigment content in pigment cells is consistent with skin color, which is related to the genetic relationship of race. Orientals are colored people, and the iris has a lot of pigment, so the eyes look black. Westerners are white, the iris has a little pigment, and the blood vessels are distributed in the matrix layer, so the eyes look light blue or green.

References:

hpe.sh/ShowNews? Article number =27266

Eye color

Eye color is a polygenic genetic feature, and the initial color is determined by the type and quantity of pigment in the iris of the eye [1][2].

There are many phenotypic variations in eye color in humans and other animals [3]. For humans, these color changes are determined by the change of the ratio of two kinds of melanin produced by melanocytes, including eumelanin and pseudomelanin [2].

Many birds have bright eyes, which are determined by other pigments, such as pterinic acid, purine and carotenoids [4]. The color of iris is influenced by three main reasons, namely, the content of melanin in iris pigment epithelial cells, the content of melanin in iris matrix and the cell density of iris matrix [5].

No matter what color of eyes, there is true melanin in iris pigment epithelial cells [2] [5]; The color change is usually determined by the melanin content in the iris matrix. Cell density in iris matrix affects the light absorbed by pigment epithelial cells [5].

[Editor] Color determines the color of eyes, which is a characteristic inherited by more than one gene [6][7]. For humans, it is known that genes of three loci are related to eye color, namely, EYCL 1, EYCL2 and EYCL3[8][9]. These genes are related to the phenotype of human eye color (brown, green and blue) [3].

Although it was previously thought that brown eyes were dominant genes, blue eyes were recessive genes. But in fact, both parents with blue eyes can give birth to offspring with brown eyes. Deciding to display the color of eyes does not follow the ordinary Mendelian genetic law, but this situation is quite rare (about 1 100 million people only 1).

All four genes must determine the same color at the same time to produce a simple color, while the opposite is a mixed color, such as cyan [6][ 10]. The color of eyes usually tends to be stable about 6 months after the baby is born [1 1].

In 2006, the EYCL3 locus was decoded [12]. Through the study of 3839 subjects, scientists found that 74% of all eye colors OCA2 can be explained by multiple groups of single nucleotide polymorphisms (SNP single nucleotide polymorphisms * * *).

In fact, the gene group of OCA2 has long been known by geneticists, because they found that when this group of genes mutates, people with this gene will become albinos. Recent studies have shown that different SNP combinations related to blue eyes and green eyes are also related to freckles, furuncles and moles, hair color and skin color.

The authors speculate that SNPs may be in the regulatory sequence of OCA2, thus affecting the expression of gene products and thus affecting pigmentation. [13][ Editor] Summary The picture on the left is the reason for the formation of iris color inferred from the above genetic research. It can be seen that dark brown, light brown and gray are all caused by the shade of melanin, blue is the color produced by scattering, and red is the color produced by albinism. When light brown is mixed with blue, it becomes green; When red and blue are mixed together, they become purple.

[Editor] Color classification The color of the observed eyes is influenced by many factors. In the picture, the same pair of eyes show different colors under different amounts of light. The human iris has only three primary colors: brown, blue and green.

Other colors of iris are variations of these three colors. The iris of albino patients is pink, because the iris has no pigment and can only show the color of microvessels.

[Editor] Brown is the most common color of human iris. Brown iris contains a lot of melanin, and dark brown iris looks like black.

Brown iris is considered to be the dominant gene of human iris, but recent studies believe that this is not necessarily correct. [Editor] The hazel hazel eyes are the result of Rayleigh scattering of the anterior iris membrane and moderate melanin.

Light brown is difficult to define. They are described as light brown or yellowish brown.

Some people think that hazel is an intermediate color between brown and blue iris. [Editor] Amber and amber are more common in other animals. They are lighter in color than brown and rarely appear in humans. They are also called cat's eyes.

In Europe, the proportion is more, or more mixed. [Editor] Green green iris is the rarest color.

The proportion of Celts, Germans and Slavs in Europe is high; Outside Europe, some Pashtuns and Turks also have green irises. So did the ancient Kyrgyz.

[Editor] Gray gray is considered as a variant of blue iris. It is the second rarest color (after green).

[Editor] Blue iris is very common in Europe, and about 8% of the world's population has blue iris. More than 80% of Nordic people such as Icelanders, Finns and Latvians have blue eyes.

Dark brown human iris. Brown human iris (this image has been processed to keep only the iris color).

Eye s 1n3r. Hazel eyes. Light brown iris with two other colors.

Amber iris cat's eye. Human amber iris with milky yellow, green and tan tones.

Green eyes. Gray eyes.

Iron gray eyes. Blue eyes.

What color are the eyes of China people?

Not all people in China have black eyes. Although there are no detailed statistics, you can take a closer look at the eyes of people you know. In fact, many people are brown. So China and other Asians are mostly brown or black.

In western countries, immigrant and non-immigrant countries are different. The United States, Canada, Australia and other immigrant countries have different races, so there is no uniform standard.

Non-immigrant countries in Europe, basically northern Europe and western Europe have more blue-green eyes, some brown eyes and a few gray eyes. In eastern Europe, about half are blue or green, and half are brown eyes.

Spain, Portugal and Italy in southern Europe mainly have brown eyes.

South America is basically brown-eyed, and Latin Americans (Hispanic or mixed with South America) are basically brown-eyed.

Black people are similar to Asians, with black eyes and brown eyes.

The iris of human eye consists of five layers: endothelial cell layer, anterior limiting membrane, matrix layer, posterior limiting membrane and posterior epithelial layer. Among these five layers of tissues, there are many pigment cells in anterior limiting membrane, stroma layer and posterior epithelial layer, and the amount of pigment contained in pigment cells determines the color of iris. The more pigment contained in pigment cells, the darker the iris and the darker the eyeball. The less pigment contained in pigment cells, the lighter the iris color and the lighter the eyeball color. The pigment content in pigment cells is consistent with skin color, which is related to the genetic relationship of race. Orientals are colored people, and the iris has a lot of pigment, so the eyes look black. Westerners are white, the iris has a little pigment, and the blood vessels are distributed in the matrix layer, so the eyes look light blue or green.

How many colors do human eyes have?

. As far as I know

There are only three colors: brown, blue and green.

Eyes of other colors belong to these three kinds.

take for example

Brown: dark brown, light brown, amber and gold (of course, it can be said to be yellow if it is not gold)

Blue: sky blue, silver blue (collectively referred to as silver)

Green is: green.

Wait, of course, this should not be all.

This is all the colors I have seen abroad (Europe)

My classmates abroad told me that her eyes were blue when she was a child, but now she has a pair of bright green eyes.

I also have an American classmate, whose eyes are a little strange. Many foreigners have eyes like this: the color is messy->; Blue eyeball, green and yellow dots near the pupil.

Can't say ugly, can only say that it is rare. ..

That's about it. If you really want to ask all the questions.

You can find an expert in this field. After all, today's race is mixed ... and it can't be compared with the previous era of judging tone.