Why is aging called "old age and yellowing of beauty"? Can premature yellowing be avoided?

Once spring is over, the beauty will fade away. When flowers fall, people will die without knowing it. From ancient times to the present, many celebrities and scholars have repeatedly lamented that time flies and beauty fades easily. Aging has become a topic that no one can escape.

So what is aging, exactly? And what does it have to do with “aging”? Don’t worry, we’ll explain in detail.

01 What is aging?

Aging is a holistic and slow process. All cells, tissues, organs and the whole body are aging synchronously, and there will be certain psychological and physiological manifestations. The most obvious physiological manifestations are graying hair, reduced skin elasticity, wrinkles, age spots, loose teeth, deafness, blurred vision, hunchback, etc. The degeneration of all aspects of the body is a manifestation of the passage of time.

In order to fight against aging, people have conducted extensive research on the mechanisms of aging.

In November 2020, the Institute of Zoology of the Chinese Academy of Sciences and its collaborators published a study online in Developmental Cell. By studying normal eyelid skin, they mapped a single-cell transcriptional map of human skin aging, revealing the molecular mechanism of skin aging, which provides a new strategy for intervening in skin aging.

The researchers worked with the hospital to obtain normal eyelid skin samples from three groups of women in their 20s, 40s, and 70s. Image provided by the research team.

However, the mechanisms that cause aging have not yet been fully understood.

02 What makes a person old and ugly?

The phrase "人老珠黄" is a common expression, which means that people are no longer valued after aging, just like pearls that turn yellow over time. But do you know? The phrase "人老珠黄" is true, literally true!

There is a transparent membrane on the surface of the human eyeball, called the conjunctiva. The inner surface of the eyelid is the palpebral conjunctiva, and the one in front of the eyeball is the bulbar conjunctiva. Below the conjunctiva is the dense white sclera.

Yellowing of the eyes is an abnormal phenomenon of eye metabolism. Both the conjunctiva and sclera will have pigmentation.

The cornea is the first line of defense for the eyeball, but its protective power is limited. After long-term exposure to ultraviolet rays, wind and sand, the lymphatic or blood circulation of the eye slows down, and some metabolic waste cannot be discharged smoothly, resulting in adverse reactions such as pigmentation.

The conjunctival epithelium shows signs of aging, and pigments accumulate in the conjunctival layer to form yellow spots. From the surface, slightly raised dark yellow substances appear in the white of the eye, and the black of the eye becomes more turbid.

Humans are exposed to external environmental stimulation over time, and the elderly are more likely to develop conjunctival pigmentation, hence the saying "people become yellow as they age".

03 How to avoid premature aging?

Ultraviolet rays can be said to be the biggest "culprit" that causes yellowing of the eyes. When ultraviolet rays pass through the cornea and reach the lens, they will be absorbed by the crystal protein, thus generating free radicals and damaging the lens cells. Long-term effects can also cause ultraviolet eye diseases.

The damage of ultraviolet rays to the eyes is caused by long-term accumulation, so we should establish the awareness of eye protection. Wearing sunglasses can effectively prevent the damage of ultraviolet rays to our eyes. In addition, the most important thing is to pay attention to the use of eyes in daily life and eat more fresh vegetables and fruits, because fruits and vegetables are rich in antioxidants and vitamin C, which help to recover from damage after exposure to the sun.

04 Two groups of people need to pay special attention to preventing ultraviolet rays

Damage to the eyes: one is children. Because children's cornea and lens are more transparent than those of adults, their ability to filter out ultraviolet rays is very weak; the other is the elderly. The elderly have been exposed to ultraviolet rays for a long time and are very likely to develop eye diseases caused by ultraviolet rays.

Nowadays, beauty lovers, especially girls, try all kinds of methods to become beautiful, such as applying sunscreen, body lotion, various hydrating, whitening and fine-line-lightening masks, using whitening devices, and going to beauty salons... In the end, they still hope to slow down the pace of aging. Here, Pangke reminds you that in addition to sunscreening your skin, don't ignore your eyes!

Creative team: China Science and Technology Museum New Media Team

Review expert: Gao Min, author of ophthalmology popularization at Xiamen Eye Center affiliated to Xiamen University

(Picture from the Internet)