Why does a solar eclipse hurt your eyes?

The sun is a celestial body that emits extremely strong light. If you don't want to hurt your eyes, don't observe directly with the naked eye, and don't observe directly with a telescope. Even if it is only for a few seconds, your eyes can easily be burned by strong sunlight, causing permanent damage. Even during the partial solar eclipse, the surface of the sun is covered by 99%, leaving a crescent-shaped ball of light, which will also cause harm to the eyes. Don't try to observe the sun with the naked eye at any stage of partial or annular solar eclipse. Only in a very short period of total solar eclipse can it be watched safely with the naked eye. But only under the guidance of professionals.

Generally, the safe and reliable way of solar eclipse observation is to use the professionally measured "solar eclipse observation card" for observation. The observation card is plated with a layer of metal on the glass or plastic film to achieve the purpose of dimming. These filters can reduce infrared and ultraviolet rays by 99.999%.

It is also safe to overlap several exposed photographic negatives and see the sun through them, because there are silver ions in the photographic negatives, which can turn the strong radiation of the sun and block the passage of ultraviolet rays.

The usual method of painting ink or blackening glass is not recommended, because the filter made in this way can not guarantee safe observation and can not completely filter the ultraviolet rays of the sun. Pour some ink into the basin to observe the reflection image of the sun, and observe the sun by dimming the computer disk core and welding the glass sheet. This can not only achieve the observation effect, but also protect the eyes. The welder's 14 lens can also be used to observe the sun safely.

It is not recommended to use binoculars to observe the sun by adding or subtracting light curtains, because it is unpredictable whether the light curtains can be reliably installed on the objective lens of the telescope. If the lamp falls off because of a gust of wind or other accidents, it means that your eyes will be disabled for life.

The observation of total solar eclipse with astronomical telescope and special dimming film (professionally produced) must also be carried out after basic training. What needs to be emphasized here is that the protective cover of the telescope viewfinder must be covered when observing. A small viewfinder is enough to hurt your eyes.

Professional astronomy enthusiasts will take advantage of the solar eclipse to take pictures of celestial bodies, but it must also be carried out in cooperation with several people, and the exercise will be carried out later. Especially when shooting, the dimmer must be turned on accurately, so as to ensure that your expensive equipment will not be burned by the sun.

Vision protection:

1. Never look directly at the sun with naked eyes or any optical equipment (such as binoculars)! Because sunlight is one million times stronger than moonlight, direct observation with naked eyes or observation through telescopes without dimming equipment will cause retinal damage and even permanent blindness. Because the sun emits strong visible light, infrared light and ultraviolet light. Ultraviolet rays not only burn the skin, but also cause rapid damage to the retina of the eyes. As long as human eyes look directly at the sun for a few seconds, it may cause permanent damage or even blindness. Macula is the most sensitive part of retina, which makes light converge and makes the image clear. Once burned, the macula can never be recovered. The "solar retinitis" in which the sun has been burned by its ultraviolet rays and infrared rays for a long time is almost incurable. Therefore, improper observation may lead to visual impairment. Before the solar eclipse, the sun was still bright. Misuse of observation glasses or direct observation of the sun will cause visual damage such as blindness. At the moment when the light comes out after the eclipse, the sun suddenly brightens, and the observer may still be immersed in the excitement visible to the naked eye. If he is not careful, he will be burned by the strong sunlight and even become blind. You may not feel it when you are burned, but you will react after a few hours. In the past total solar eclipse viewing, this kind of injury often occurred, and some even caused the viewer to be permanently blind.

2. When shooting the total solar eclipse, the photographer must add Bard film during the partial solar eclipse, and pay attention to the damage to the eyes caused by the sudden sunlight during the' raw light'. When taking pictures with a camera, please don't aim the lens directly at the sun. After the sunlight is focused by the lens, it is easy to burn out the photosensitive CCD or CMOS. Please use special filters to protect the camera.

Social security:

During the total solar eclipse, there will be five or six minutes of "darkness", which will have an impact on the natural environment and the normal operation of society with the phenomenon of temperature drop and abnormal animal behavior. The sudden appearance of "dark night" may bring security risks to road traffic, shipping, aerial and field work, construction, medical treatment, teaching, business activities and social security.

Scientific observation method:

1, use special eclipse observation glasses. Special solar eclipse observation glasses are glasses made of special high-efficiency filter film.

2. Observe the projection image of the sun with pinhole imaging principle. The so-called pinhole imaging method refers to sticking some small holes on paper or crossing your hands, and observing the projected image of the sun on the ground through small holes or fingers.

3. Telescope projection method. Don't shake your hands, or the shadow of the sun will run back and forth. If you look at the sun directly through a telescope, you must use a filter.

4. The welder's 14 lens can also be used to watch the sun safely.

Other sunglasses, multi-layer sunglasses, compact discs, ordinary telescopes, X-rays (with images), ink glass, blackened glass, sunglasses, a plate of ink, medium-density filters for photography and polarizers are all unsafe.

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