Use your eyes scientifically—is blue light protection all you need?

Modern Society

Mobile phones and computers

It has become a part of work and life

Essential tools

Looking around

Everyone's life

Flooded by screens big and small

Dear hard-working workers,

Sitting in front of the computer all day

at the same time

Students taking online classes

Struggling in front of the screen

I finally got through the hardship of daytime life.

In the dead of night

Lying in bed, I couldn't help myself

Swipe! Mobile!

As we spend more and more time in front of screens

The light gradually disappeared from everyone's eyes.

At the same time, many people began to worry about

Your eye health

Because of long time in front of the screen

Eyes are tired

Swelling, dryness, foreign body sensation, blurred vision

Visual fatigue caused by excessive eye use not only affects work and study efficiency , but also endangers everyone's health and quality of life to a great extent.

In response to these eye health problems, a variety of products have appeared on the market. For people who work with fluorescent screens and use mobile phones and computers a lot, **anti-blue light glasses have been launched to isolate ultraviolet rays, radiation and harmful blue light.

Many glasses nowadays claim to

Has the function of blocking blue light

Why do we need to protect against blue light?

What’s the science behind blue light blocking glasses?

To use your eyes scientifically, is blue light protection all you need?

Let’s look down together!

What is Blue Light?

In recent years, more and more popular anti-blue light consumer products have appeared

But what is blue light?

Blu-ray disc! (×)

Image source: Baidu

The light we see in our daily life is the visible light with a wavelength of 380nm-720nm.

Red light with a wavelength longer than 720nm is invisible to our naked eyes and is called infrared light. Similarly, purple light with a wavelength below 380nm is called ultraviolet light. Visible light with a wavelength between 385-505nm is called blue light, which has a short wavelength, high energy and strong penetrating power.

The so-called harmful blue light in life refers to short-wave blue light with a wavelength of 415nm-455nm.

Spectrum

Image source: Zhihu

The impact of blue light

Damage to retinal cells

Experiments have found that if the blue light intensity exceeds 1500lx (lux, unit of illumination) and directly irradiates the retina for more than 3 hours, it will cause apoptosis and a decrease in the number of retinal cells.

Causes visual fatigue

Image source: Zhihu

However, the wavelength of blue light is shorter, which makes it focus in front of the retina. When the proportion of blue light in visible light is too high, it may aggravate the color difference distance and make the vision blurred, requiring more adjustments of the eyes to see clearly, causing visual fatigue.

Causes insomnia

In addition, blue light can stimulate the production of cortisol and inhibit the secretion of melatonin. If you are exposed to too much blue light before going to bed, it will inhibit the secretion of melatonin and cause insomnia.

Causes depression

I heard that blue light can make people depressed?

Blue is a serious and calming color that can regulate nerves and calm the mind. Excessive exposure to blue can also cause people to feel depressed.

Therefore, people who are in a bad mood or have a sensitive personality should not be exposed to the color blue.

Otherwise, it might aggravate his depression.

Other hazards

Image source: Baidu

In addition to depression, insomnia, eye fatigue, and decreased vision, blue light can also cause pigmentation, cataracts and other hazards.

Positive effects of blue light

Of course, blue light also has positive effects on the human body, for example, it regulates the body's biological clock. Studies have shown that blue light with a wavelength between 400nm and 520nm is very important for regulating melatonin levels.

Overall, blue light needs to be protected!

Anti-blue light principle

Common blue light protection has two working principles

One absorbs blue light, the other reflects blue light

Absorbing blue light

Image source: Baidu

Reflecting blue light

Image source: Baidu

Absorbing blue light is done by adding anti-blue light factors into the lens material of the glasses. When harmful blue light passes through the lens, the anti-blue light factor will absorb the harmful blue light, thus achieving blue light protection.

To reflect blue light , a layer of optical film is coated on the lenses of the glasses. This optical film can reflect harmful blue light bands through light interference, thereby achieving the effect of blocking blue light.

How to choose anti-blue light products?

Although blue light is harmful

But now on the market

Blue light protection products vary greatly

Improper protection may also aggravate visual fatigue

Therefore, scientific standards are needed

In July 2020, the new national standard GB/T38120 "Technical Requirements for Optical Health and Light Safety Application of Blue Light Protective Film" came into effect.

This standard is based on the different effects of blue light in different bands on the human body, and has higher requirements on the blue light transmittance of each band of the product.

For the 415nm-445nm band corresponding to harmful blue light, the light transmittance is required to be less than or equal to 80%, while for the beneficial blue light band above 445nm, the transmittance is required to be greater than 80%.

This can not only effectively block harmful blue light that poses a health and safety risk to the human body, but also allow beneficial blue light that regulates the human body's physiological rhythm to pass through effectively.

Using your eyes scientifically is not just about protecting against blue light

In recent years

Whether it is a student group or an adult group

Eye health problems are growing

To protect eye health and prevent myopia,

Chinese parents try their best to

Massage, acupuncture, dietary therapy and other folk remedies

Exploding all over the country

↓

Questions about preventing myopia

Source: Zhihu

Of course, you should eat foods with homophonic sounds for nourishment:

Fish eye, dragon eye

But in fact

These methods often

Just to comfort myself.

To prevent myopia and reduce myopia

No obvious effect

besides

Some of the treatments circulating in the world spread like wildfire

"Peeling edamame", "Flashing Exercise",

"Mindfulness Therapy" etc.

It's even more ridiculous

Fuck in the blink of an eye

Image source: Internet

How to use your eyes correctly?

So how should we use our eyes correctly?

Here are some specific suggestions:

Don't overuse your eyes, and take a break in time

Follow the 20:20:20 rule to protect your eyes. That is, every 20 minutes, look up at a distance of 20 feet (about 6 meters) for 20 seconds to relieve eye fatigue.

20:20:20 rule for eye protection

Image source: Hebei Provincial Health Commission

Ensure adequate light when using your eyes

In addition, read in a well-lit environment. It is not advisable to play with your phone for a long time in the dark late at night.

Maintain good living habits

Participating in outdoor sports, ensuring adequate sleep, and maintaining physical and mental happiness can all have a positive effect on relieving eye fatigue and preventing myopia.

Summarize

Eye Health

It is the result of multiple factors.

Scientific Eyes

The key is to develop good eye habits

Eye health is not trivial

Bright eyes

Only then can we appreciate the world better!

Source: Tanzhen Technology Review