Why can t a total solar eclipse be seen with the eyes?

Because I am afraid that the sun will burn the cornea, it will hurt the eyes.

Of course, the sun's light is so strong that looking directly for too long can cause retinal damage and cause loss.

No. When observing a solar eclipse, it is important not to use the naked eye directly** to avoid strong sunlight burning the eyes, causing solar ophthalmia and solar eclipsal retinopathy, and in severe cases, it can cause permanent visual damage, even if it is a partial solar eclipse, it cannot be directly observed with the naked eye.

Eclipse observation method.

1. Aperture imaging observation method: Aperture imaging allows sunlight to pass through a small hole, and a white screen is placed 1 meter away after opening the small hole, so that the sunlight beam shines on the white screen through the small hole and projects a image of the sun. This projection observation method can be taken from local materials.

For example, a board with many holes, a loose and broken straw hat, or even the fingers of both hands can be crossed to project a series of images of the sun on the screen.

2. Telescope projection observation method: you can put the binoculars on the tripod and put the whiteboard behind it, so that the magnified image of the sun can be projected. Never hold a telescope directly to the sun, if you use a telescope to look directly at the sun, be sure to use a filter.

3. Goggle observation method: The most common goggles are the special goggles for welders with a shading number of 14, which can be bought in the welding equipment market.

4. Bard film observation method: Bard film is a metal-coated resin film, which can be used for visual and photographing. It is very thin, the optical quality is excellent, and the Bard film that can be bought at the moment is available in two densities, which can be used for visual vision and can be used for taking pictures).

5. Observation of solar eclipse glasses: There are many special observation glasses for solar eclipse on the market, and you must pay attention to the choice of observation glasses when buying a slim early line.

If you use the naked eye to directly ** total solar eclipse, after watching it, there will be a black shadow in front of the eyes, or a black area in front of the eyes, which will look as if it is blocked by clouds and fog, and it will be accompanied by discomfort such as visual distortion and discoloration.

It is caused by the infrared rays in the sunlight directly irradiating the eyes. Infrared heat energy is very strong, and can pass through a very thick atmosphere or clouds without dispersion, so when you look directly at the sun with your eyes, infrared light will pass through the cornea, lens, vitreous body of the eyeball to the macular area of the retina, after the light is absorbed by the pigment epithelial cells, it is converted into heat energy, burning the macular area, making the macular area edema, bleeding, and even perforation.

**Without proper protective gear during a partial solar eclipse, it can also cause burns to the retina. No matter how long the retina has been exposed to the sun, this damage can lead to permanent damage to vision. When the retina is burned, we may not feel pain, but this visual symptom will appear at least a few hours after this damage appears, so it is important to take measures to protect your eyes during a total solar eclipse.

Because sunlight is a million times stronger than moonlight, it cannot be directly ** with the naked eye or through a telescope without light-reducing equipment, otherwise it is easy to cause retinal damage and even blindness.

Medical experts point out that "solar retinitis", which causes burns to the macula of the retina due to direct sunlight and infrared rays for a long time, is almost impossible.

The macula of the retina is the most sensitive part of the retina, which allows light to converge and make the image clear. Once burned, the retinal macula will never recover.

Pointing cameras, telescopes and other observation instruments directly at the sun will not only cause damage to the lenses in the instruments, but also burn out the retina directly due to the sunlight gathered by the optics.

During a partial solar eclipse, it is safer to wear a pair of total eclipse goggles or to use a basin of ink with ink to pass through the reflection**.

When observing a total solar eclipse with a telescope, be sure to add a filter in front of the eyepiece or detector to avoid burning your eyes. During a total solar eclipse, you can use the naked eye directly**, and remove the filter or filter before shooting with a telescope.

A total solar eclipse without wearing a protective solar filter can cause serious eye damage, including blindness.

The naked eye is only allowed during a brief total solar eclipse, and the naked eye** is dangerous during a partial solar eclipse, which can cause serious damage to the eyes and even blindness. Ordinary sunglasses, homemade filters, unfiltered cameras, binoculars, and other optical devices will not protect the eyes from a solar eclipse.

Only dedicated solar filters that comply with international safety standards and ISO 12312-2 standards are safe to use, or special solar filters can be purchased and placed on cameras, binoculars and binoculars for safety**.

Due to the huge commercial interest, many manufacturers are making professional solar eclipse glasses, and many of them are sold out, but American astronomers have put together a list of products that show which are ISO 12312-2 compliant and approved by NASA for safe eclipse glasses.

The Atomic Energy Commission (The AAS) has warned that many counterfeit eclipse glasses will be used by August 21, so consumers should be careful when buying them.