One of the beauties of life is how we make use of a hostile environment to sustain ourselves.

We breathe by burning a highly volatile and corrosive gas - oxygen - for energy.

Also for energy - we turn food into a dangerous substance that damages the linings of our blood vessels and our nerves - glucose (sugar).

But we couldn't power ourselves with oxygen and sugar if the planet were not receiving a steady stream of energy from the star we revolve around - sunlight.

Obviously, there'd be no life on Earth without it. 

Also, we need it to optimize our health.

But too much of it damages and ages our skin, so finding the proper balance is essential to maximize your appearance, especially your face.

Skin Vitality and Youthfulness Demands a Steady Stream of New, Healthy Cells

Like the rest of your body, your skin is comprised of cells.

But - like all living things - cells grow old and die. Skin cells are often damaged by your surrounding environment: dust, smoke, hot and cold air, pollution, irritating chemicals, low humidity and so on.

Therefore, to ensure a constant re-supply of young and vigorous skin cells, existing cells must multiply and divide into new cells.

They have to replace the skin cells that are damaged or have grown old.

Skin cells do this like all other cells. You saw the movie in Science class.

Their DNA splits down the middle and then forms the basis for two new cells.

DNA is a double helix staircase with steps made up of four biochemicals:

1. Adenine (A)

2. Cytosine (C)

3. Guanine (G)

4. Thymine (T)

To form the steps connecting the two sides of the double helix, these four connect in combinations 4 letters long: ACTC, GTAA and so on.

When cells multiply, these 4-letter steps break apart in the middle. Then they create new, hopefully identical, strands, for the new cells.

Where the Process Goes Wrong

When your cells' DNA replicates exactly, the new cells function just like the old - and they stay young and vigorous.

And look youthful.

When DNA is damaged, however, it can't split exactly. Therefore, it can't create new cells that are exactly the same as the new. 

Important information is lost. Errors are introduced - like a poorly photocopied picture.

The new cells just don't work as well.

They don't look as good.

Over time, the damage compounds.

So your skin looks drier, duller, dotted with age spots and just plain older. Lines, wrinkles, crow's feet, discoloration, redness, irritation - everything that makes people appear old.

How Sunlight Causes These Skin Problems

The ultraviolet light in sunlight fuses the pairs of T's in your skin's DNA. 

That is, wherever your DNA has two TTs next to each other, UV radiation fuses them.

That forms hard lumps called thymine-thymine diamonds.

Clearly, these T-T diamonds interfere with the process of cellular replication.

When they have T-T diamonds, the DNA strands can't separate easily like a zipper. 

What really damages your skin, however, is how this stresses your skin cells when they repair the damage.

Over time, this stress accumulates. You don't pay attention when you're 22 and enjoy sunbathing. 

But when you're 40 . . . you notice.

And it's too late to go back to age 22 and relax in the shade.

Health Benefits of Sunlight

1. Sunlight triggers our bodies to synthesize Vitamin D.

2. Your eyes need exposure to the full spectrum of sunlight.

3. The sun - and the angle of its current position in the sky - cue your body's many biological clocks.

That keeps you tuned to the daily circadian rhythm, which you need for optimal health.

When your body is in sync with the time of day, you feel energetic in the morning and tired late at night. Your body falls sleep much more easily.

4. When you eat a lot of plants, especially leafy greens, you have chlorophyll circulating in your blood from them.

When you're in the sun, its radiation acts on that chlorophyll to help regenerate the antioxidant CoQ-10.

No Matter What Your Current Age

Avoid sun damage.

A small amount of sunlight is good for you. How much depends on your skin color.

The lighter your skin, the more at risk you are for sun damage. Very fair-skinned people shouldn't stay in the sun more than five or ten minutes without sunscreen.

If you do get sunburned, you were out too long. 

Use sunscreen if you'll be outside for longer than what's safe for your skin.

Or wear protective clothing.

Or stay in the shade. That's why someone invented beach umbrellas.

Avoid sun exposure when the sun's rays are the most direct - that is, the strongest: 10:00 AM - 2:00 PM. (If you're on Daylight Savings Time, that's 11:00 AM to 3:00 PM.)

Throughout Asia, women commonly carry umbrellas in dry weather to protect the skin of their faces from sunlight.

People carrying parasols to protect their skin date back at least 4,000 years to ancient Egypt. At times, parasols have been fashionable in the West, not simply in Asia.

It's time to make parasols fashionable again.

https://www.aad.org/public/everyday-care/sun-protection/sun-damage-skin

https://en.wikipedia.org/wiki/DNA

https://www.youtube.com/watch?v=-6Laa2LiS2E

https://www.yalemedicine.org/conditions/sun-damage

https://nutritionfacts.org/video/how-to-regenerate-coenzyme-q10-coq10-naturally/