Not only the skin, but also the eyes! Choose such sunglasses.

In the hot summer, the dazzling sunshine not only makes people worry that their skin will be tanned and sunburned at once, but actually even their eyes are exposed to ultraviolet rays. But most people usually only remember to apply sunscreen on their skin, but they don't think that their eyes need sunscreen! When the sun is dazzling, we need a pair of safe and comfortable sunglasses to protect our vision health, especially in four cases, sunglasses can come in handy!

Effect of strong light on eye health

Visible light is between 400 and 760 nanometers. The shorter the wavelength, the greater the damage to the eyes, and the more likely it is to cause glare and retinal damage. In particular, the blue-violet light with the wavelength below 450 nm is prone to light dispersion, which reduces the definition; In addition, invisible light: long wave ultraviolet (UVA) between 314 and 400 nm and medium wave ultraviolet (UVB) between 280 and 320 nm. These two kinds of high-energy rays can even pass through the cornea and lens and directly drive the retina, thus causing eye aging and even increasing the risk of cataract.

At present, known eye diseases caused by ultraviolet rays include:

Cataracts/

Outdoor activities, exposure to the sun for a long time, if you don't do a good job of eye protection, coupled with the extensive use of 3C products indoors, will absorb the blue light emitted by the screen, which will lead to the overload of intraocular lens, accelerate the degradation and deepen the risk of cataract.

Macular lesion/

Right behind our eyeballs, there is a small part in the center of the retina, which is an important key to help protect our vision health, called macula. High-energy light with short wavelength, such as blue light and ultraviolet light, is one of the causes of premature macular damage and lesions.

Retinopathy/

The retina is the protagonist of the eye. When light enters the retina, it will be responsible for imaging the objects in front of us. However, under too strong ultraviolet radiation, the retina will be prone to pathological changes and even lead to blindness.

Photokeratitis/

In summer, young people like to go to the beach and play, while elders may run to the stream to enjoy the cool. No matter in the mountains or at the seaside, there is a crisis of excessive ultraviolet rays. Even like skiing abroad in winter, the strong light reflected by snow can cause eye damage and lead to light-induced keratitis. When the sun is strongest at noon, even staying at the seaside for a few minutes 10 may cause light-induced keratitis.

What kind of sunglasses do you have?

Don't think that sunglasses are just fashion accessories. In fact, they are necessary tools to protect eyes. Buying is not just about the appearance, but the anti-ultraviolet function of the lens is the key. An excellent pair of sunglasses should be able to filter out 65,438+000% ultraviolet rays. The types of lenses can be divided into polarized lenses, dyed coated lenses and color-changing sunglasses.

When the sunlight or strong light of the polarizer shines on the lens, the light will diverge in different directions, causing glare and affecting vision. Therefore, a polarizing film is added between the lenses of the polarizer to filter out the strong reflected light from the earth and remove the dazzling polarization in the horizontal direction, so that the light becomes clear and our sight will not be too dazzling. Polarized lenses are suitable for snow, seaside, mountain climbing, fishing and water activities. In addition, the yellow lens can prevent glare, which is suitable for driving at night and increases the brightness of the visible area.

In addition, there are some special brands of polarizing lenses, which add progressive design and aspheric design to the inner surface, which is helpful to increase the broader field of vision when hyperopia. Aspheric design can reduce the distortion and jitter of visual field and make eyes more comfortable.

Coated lenses Coated lenses are made by vacuum coating using the principle of light wave interference and various materials with different refractive indexes. Common ones are mercury-plated lenses, colored silver-plated lenses and multilayer coated lenses. Multilayer coated lenses use more than one film to enhance the lens function, but the manufacturing process is also complicated.

Dyed lenses. This is the most common form. There are different colors of lenses, such as gray, green, brown or brown, yellow and blue lenses. When you look through gray, brown and dark green lenses, the object will not deform, which is currently recognized as the most suitable color for sunglasses lenses. However, lenses with special colors will still affect the visual depth in the case of dark light, so they are suitable for wearing in strong sunlight.

Color-changing lens When ultraviolet rays are irradiated on the lens, the coating on the lens will change chemically, changing the internal molecular structure and turning the coating into a darker color, such as gray or brown. Then when you go indoors or to a place without ultraviolet radiation, the coating will slowly change back to its original transparent state, which is equivalent to wearing a pair of myopia glasses, and can also achieve the effect of sun protection and eye protection.

Choosing an excellent pair of sunglasses can protect your eyesight and prevent pathological changes. Remember to choose the type and material of the upper lens and frame, and remember not to move outside when there is too much ultraviolet light. When you go to places with high ultraviolet rays such as the seaside and mountainous areas, you must remember to wear sunglasses to achieve comprehensive protection of your eyes!

When going to the seaside and beach, don't forget to wear a pair of anti-UV400 polarized lenses to protect your eyes. There are 100 kinds of sunglasses, and it is better for eyes to pass the test of anti-UV400 polarized lenses.