Purchase color-changing glasses for myopia. If you are advertising, please stay away!

If the craftsmanship and materials are the same between imported and domestic products, there is almost no difference.

It is nothing more than discoloration of the base and discoloration of the bottomless discoloration film

The market price is 500~1000, which is of good quality.

Photochromic glasses, also known as anti-sunglasses, are mainly used in outdoor, snowy, and indoor workplaces with strong light sources to prevent eye damage from sunlight, ultraviolet rays, and glare.

The production and function of photochromic mirrors: The lenses are made of optical glass containing silver halide microcrystals. According to the principle of reversible light-color interconversion reaction, they can quickly darken under sunlight and ultraviolet rays, and completely absorb ultraviolet rays. , has neutral absorption of visible light; when returned to a dark place, it can quickly return to colorless and transparent. The photochromic properties of this lens are permanently reversible.

The functions of glasses are nothing more than two. One is to correct vision, allowing people to see distant or near scenes clearly, and the other is to reduce the stimulation of strong light on glasses, thereby protecting the eyes. role. The former is done by glasses for nearsightedness or farsightedness, and the latter is done by sunglasses.

With the development of science and technology, people have now invented a kind of glasses that combine two functions in one - color-changing glasses.

When this kind of glasses is exposed to strong light outdoors (or under the sun), the color of the lenses will gradually darken, which can protect the glasses from strong light stimulation; when entering indoors, the light will weaken and the color of the lenses will gradually become lighter. Ensures normal observation of the scenery.

The discoloration principle of photochromic mirrors: The main component of ordinary glass is silicate, and the optical glass used as spectacle lenses also contains potassium. This kind of optical glass has high hardness, is not easy to wear, and has good clarity. In the lens glass for making color-changing glasses, in addition to the general raw materials, an appropriate amount of tiny grains of silver halide and copper oxide must be added. After the lens is made, Silver halide will decompose into silver and halogen when exposed to strong light:

2AgX=2Ag X2

Because the silver particles are dark, the color of the lens becomes darker. When the light becomes dim (weak), silver and halogen recombine under the action of the catalyst copper oxide to form silver halide:

2Ag＋X2=2AgX

Then the color of the lens changes again became lighter. So the secret to the discoloration lies in the decomposition and recombination of silver halide under different conditions. Experiments have proven that after the lens of color-changing glasses is exposed to sunlight for 5 minutes, the strong light passing through the lens can attenuate to 50% of the original value; when the lens is left out of the sun for 5 minutes, the light can be restored to 23%, and after about an hour, it can be completely restored to the original value. true color.

Since the added silver halide and copper oxide have been integrated with the optical glass, the color-changing glasses can change color repeatedly and can be used for a long time. They can not only protect the eyes from strong light stimulation, but also correct vision. effect.

Three types of people who should not wear photochromic glasses:

1. Children who go to school have immature physiological functions and cannot accurately adjust the light and dark parallax. They wear photochromic glasses to read the words on the blackboard. The words are laborious and blurry, which will damage your glasses prematurely.

2. For people with myopia above 600° who have poor corrected vision and wear color-changing glasses, their eyes seem to be covered with a layer of fog, which can aggravate visual fatigue and cause myopia to worsen.

3. The eyes of people over 45 years old have begun to age. Reading and writing articles require bright light, and bright light will deepen the color of the photochromic glasses, dilate the pupils of the eyeballs, and cause anterior vision. Narrow chamber angle and poor drainage of aqueous humor can easily induce glaucoma.