Can you see the total solar eclipse with the naked eye? Why? Are sunglasses all right?

No, remember not to look directly at it with the naked eye. However, ordinary sunglasses have low shading rate, and invisible harmful light may still enter the eyes. Telescopes can concentrate light, so it is more dangerous to see the eclipse with the naked eye. Don't use a camera without a visor on the lens, otherwise it is likely to damage the lens. I was just reading this information.

In order to watch the total solar eclipse better and healthier, you should read the following information carefully, which is very helpful.

You can't look at the sun naked.

Regarding the questions that many netizens care about, can you see the sun naked? Professor Yi said that when looking directly at the sun, people's eyes have a structure called pupil, which acts like the aperture of a camera and adjusts itself with the intensity of external light. When the camera takes pictures, the aperture will be adjusted very small if the light is strong, and it will be larger if the light is weak. Relatively speaking, the function of the pupil is the same. By adjusting the size of the pupil, the light entering the eye can be adjusted. No one can look directly at the sun. When looking directly at strong light, people will instinctively avoid it. For example, ordinary people need to wear sunglasses when they are outdoors, even if they don't look directly at the sun, so that their eyes will feel comfortable.

It hurts to see the eclipse with the naked eye. The culprit turned out to be the "lens"

Watching an eclipse with the naked eye will hurt your eyes. What are the main "injuries"?

Professor Yi explained that there is a structure in the eye called the lens, which acts as a convex lens, and it can focus light on the retina, thus producing vision.

The so-called naked-eye eclipse is actually a photochemical damage to the eyes, that is, the light is too strong. Through the refraction of the pupil and the lens, the light converges to a small point and reaches the fundus retina, which makes the retina receive a particularly large amount of energy, and the temperature of this part of retina tissue rises, resulting in a series of biochemical changes.

Seeing that the eclipse hurts the eyes, 1 ~ 4 hours later, symptoms will appear.

Watching a solar eclipse hurts the eyes, which is often called "solar eclipse omentum". What is the omentum of an eclipse? Eclipse omentum: medically known as solar opacity, refers to macular degeneration and photochemical damage caused by sunlight.

Professor Yi said that when people's eyes are looking at things, the most important thing is that the macula is working. Macula is a part of retina, and its size is about1.5 mm. People look at things mainly with macula. Retinopathy caused by naked eye eclipse mainly refers to macular lesions on the retina: macular edema and macular burn.

The most serious macular degeneration caused by naked eye eclipse is mainly macular burn, which leads to perforation and macular hole. After macular hole is formed, the general vision is generally below 0.2.

What's even more frightening is that when such a serious eye injury as "macular hole" is caused, the patient actually doesn't feel anything at first, and it takes 1~4 hours for symptoms to appear. Why is this? Professor Yi analyzed the author's problem from the physiological function of the retina: the macula is mainly a photosensitive organ, and there are nerves related to light sensitivity on the macula, but there are no nerves related to pain, macular perforation, and the patient has no feeling related to "pain". The three symptoms of macular burn, "decreased vision, distorted vision and central scotoma", did not appear until 1~4 hours after the burn.

Even watching the solar eclipse with naked eyes will not lead to "blindness"

People see things mainly through the macula. Burning a hole in the macula will only affect the central part of one's vision. That is to say, after macular burn-through, what the patient looks at is invisible, but covered by a black shadow, which is called "central scotoma" in medicine, but the peripheral vision except "central scotoma" remains normal, and the eyes can still have a part of vision through the corner, and the vision is about 0. Blindness refers to the complete loss of light perception, which has a strict definition in medicine: vision.

The degree of vision recovery after total solar eclipse depends on the degree of macular burn.

Professor Yi told the author that the recovery of vision prognosis depends on the degree of macular burn. The lighter the degree, the better the recovery.

The degree of eye burn depends on: viewing time, pupil size, exposure time and intensity. The longer the naked eye looks directly at the sun, the greater the intensity of the sun, and the longer the macula is exposed to the focused sun, the more serious the macular damage.

Generally speaking, as long as there is no macular hole, vision can be restored or nearly restored. After the formation of macular hole, the nature of retina has changed and can not be recovered generally.

Main examination and treatment methods of eye injury caused by total solar eclipse

Doctors can find that macula can be found in the early stage, abnormal reflex, pigment epithelial changes, uneven pigment, pigment migration and pigment changes after a few weeks. In the process of seeking treatment, patients should pay attention to finding a professional ophthalmologist for examination. The main inspection methods are: color photos, OCT, etc.

Treatment methods are limited, mainly relying on the self-repair ability of omentum, while giving drug treatment.

Mild injuries such as macular edema are mainly neuroprotective drugs: vitamin B, folic acid, ganglioside, mecobalamin and other drugs. If macular edema is severe, hormone therapy such as prednisone can be given. Generally, the course of treatment lasts for half a month, and only a few hundred yuan can cure the patient.

More serious macular degeneration, as long as it has not reached the level of macular perforation, can be recovered or nearly recovered within half a year after treatment.

All strong light will cause retinopathy, but the nature is different.

"Of course, the damage of strong light to the eyes also includes the damage to the cornea. But they are relatively chronic and can be recovered after treatment, "Professor Yi further explained. "For example, the welder accidentally forgot to bring eye protection tools when welding, and the strong light generated during welding suddenly acts on the eyes, mainly causing corneal burns. Patients with corneal burns will have intense eye pain. Corneal burn can be recovered after 2-3 days of treatment. However, the burning of the retina by strong light is a serious injury in a short time, and it is often irreversible. At present, only lasers and sunlight can cause macular perforation. "

Who is not suitable for watching the total solar eclipse?

Who is not suitable for watching the solar eclipse? Professor Yi told the author: Generally speaking, as long as the eclipse is well watched, it will not hurt too much. Compared with healthy people, people in the following four situations are at greater risk of eye sunlight damage, so patients in the following four situations should take better protective measures and pay attention to protecting their eyesight when watching the total solar eclipse:

1. High myopia

Patients with high myopia have thin retina, poor quality and poor tolerance to sunlight damage.

2. fundus diseases with poor retinal quality

Including "I have suffered from various retinopathy, retinal rupture, retinal lamellar perforation, retinal surgery, and now I have retinopathy, such as" age-related macular degeneration, diabetic fundus changes, and macular X-rays. And ocular contusion, uveitis, etc.

The people with poor eye health are susceptible to retinal damage caused by solar eclipse, and this group of people should pay more attention to preventive measures.

What should I do about the once-in-a-century total solar eclipse?

The author suffers from high myopia and loves the beauty of solar eclipse. When watching a solar eclipse, how can we "see the most beautiful total solar eclipse" and "protect our eyes"? With this question, the author interviewed Mr. Yang, an astronomy enthusiast.

Yang is a member of Guangdong Astronomical Association and the main person in charge of Shrimp Star Network.

Staring directly at the sun for more than 10 seconds can lead to permanent visual impairment.

Teacher Yang told me that a complete total solar eclipse includes five stages: initial loss, heavy food, heavy food, light production and last contact. When you eat a lot, that is, when you eat a total solar eclipse, the naked eye will not cause eye damage, let alone blindness. But generally, you can't look at the sun directly with the naked eye except for eating for a few minutes, because the strong light of the sun will sting your eyes, and staring at the sun directly for more than 10 second will cause permanent visual impairment. In addition to the total solar eclipse, you can look directly at the sun for a few minutes with the naked eye, and don't look directly at the sun at other times. Therefore, safety is always the first criterion for watching the total solar eclipse. Mr. Yang said: "There are very professional astronomy enthusiasts around me and in our amateur team. They know how to protect their eyes and do a good job of prevention. So far, nothing has happened around me that hurts their eyes because of watching the sun."

Adopt scientific observation methods.

1, which observation methods are safe?

So, when watching the eclipse, which observation instruments are necessary? What observation methods are safe? Teacher Yang told the author: Generally, when watching an eclipse, astronomy enthusiasts will buy filters and Budd films to filter out the strong sunlight in front of the telescope. Both the filter and the Budd film play the role of color filtering. The power of sunlight is too great, too bright. Only by filtering out the strong light with filter products can we see the sunshine and protect our eyes. Ordinary citizens' observation method of total solar eclipse is actually very simple. As long as the qualified filter products are used correctly, we can observe through the filter products. General filter products include: filter, Budd film, and multiple lenses superimposed as filters. Of course, the safest way to observe is to watch the solar eclipse indirectly with a pinhole observer, but Teacher Yang said: "This method is generally used when observing the sun. This method is not recommended to observe the total solar eclipse. Comparing the total solar eclipse is a spectacular astronomical phenomenon that is rare in a hundred years. Observing it through a filter is a good choice. "

Mr. Yang also emphasized that he warned ordinary citizens not to use floppy disks and color negative films as filters, especially not to use blackened glass and ordinary sunglasses to watch the sun, because their infrared dimming rate is extremely low, which will cause permanent damage to their eyes.

2. How to test the quality of purchased Bader membrane?

What brand of filters do you buy? Mr. Yang told the author that there is no uniform label. Bader film is mainly produced by Bader Company. When buying, you can test the quality of the product in a small way. By observing some high-power bulbs, the filtering performance of this filter product can be tested. If the product quality is good, the wick of the bulb can be seen through the filter product. In fact, the sunglasses on the market are mainly made according to these two products.

3. When observing with eclipse glasses, scientific observation methods should be adopted.

● Before using eclipse glasses every time, please carefully check whether the glasses are in good condition. Please stop using them immediately if they are damaged. Children must use it under the correct guidance of parents and teachers.

● Watch the eclipse for no longer than 3 minutes, and rest for more than 30 seconds before continuing to watch. People who suffer from eye diseases and are not suitable for watching eclipses should not use eclipse glasses.

● Wear eclipse glasses 30 minutes in advance. Adapt to the dark environment

● Remember to "pick one by two". That is, wear partial eclipse glasses in the partial eclipse stage to adapt the eyes to the darkness; In the stage of total lunar eclipse, after the moon completely blocks the sun, take off the eclipse glasses and observe them with naked eyes for about 4-5 minutes; After the total lunar eclipse, you should wear eclipse glasses to watch it immediately.

In addition to the choice of filter products mentioned above, some people want to record the spectacular sky phenomenon of total solar eclipse through photography. It should be noted that you can't shoot directly with the camera (you must add a special filter) to avoid damaging and burning the camera. In the choice of shooting camera, it is best to choose film camera.

Mr. Yang told the author that as long as the place where the eclipse is seen is empty, it can be observed in the direct sunlight and where the sun is not covered by clouds. There is no need to go to the mountains or grasslands to watch, so pay attention to the local weather when choosing the place to watch the total solar eclipse. When the total solar eclipse occurs, the sun suddenly disappears, the temperature drops rapidly, and the pressure and wind direction change. Usually this time will last for a few minutes. At this time, the public should pay attention to all aspects of traffic safety and warmth keeping.

Mr. Zhang is showing the solar eclipse observation mirror.

Teacher Zhang told the author that the team watching the eclipse also made relevant regulations on ensuring eye health: the Bard film is directly attached to the telescope, and members are forbidden to take off the Bard film without authorization. When the total solar eclipse comes, the team staff will prompt them to take off their chin mask. After the total solar eclipse, the partial solar eclipse comes. When the sun feels dazzling, the staff will remind members to put back the Budd's membrane in time to avoid retinal damage during the solar eclipse.

Mr. Zhang called on ordinary people and children not to watch the solar eclipse out of curiosity, but to watch the sun under the guidance of a special person to avoid permanent damage to their eyes.

The author's conclusion

Although the once-in-a-century solar eclipse is rare, it is more important to do a good job of eye protection. Don't "look forward to the eclipse", "look forward to" or even "look through the autumn water" because you are not careful. Beautiful scenery is precious, and the price of vision is higher. When watching the solar eclipse, we must pay attention to using scientific and safe methods.

Remember to remind friends around you, because avoid unnecessary harm. If you don't have special eclipse glasses, it's best not to watch it by the earth method, and then watch it with the naked eye when the total solar eclipse is completely black. After all, although it is once in 300 years, health is more important!

I didn't know until tonight that I didn't buy an eclipse mirror in advance, so I can only watch part of it tomorrow ~ regret it! ! ! !