What is the principle of photochromic glasses that change color due to illumination?

Chromic lenses, which turn black in daylight, protect the eyes. In the dark, it can be restored to its original state.

Appearance. Magical photochromic mirrors! Its discoloration principle is related to the properties of silver halide.

The mystery of color-changing glasses is in the glass. This special type of glass is called "photochromic" glass. in manufacturing.

In the process, light-sensitive substances such as silver chloride and silver bromide (collectively referred to as silver halide) are pre-incorporated

There are a small amount of copper oxide catalysts. The spectacle lenses went from no color to light gray, tan and back to dark glasses.

Ordinary glasses are all "magic" of silver halide. In the glass of the photochromic glasses, there is exposure with photosensitive film.

The process of change is very similar in light imaging. Silver halide decomposes by light and becomes a lot of black silver particles.

Evenly distributed in the glass, the glass lenses appear dull and block the passage of light, which is called dark glasses. But.

Yes, unlike the case on photosensitive film, the silver atoms and halogen atoms formed by the decomposition of silver halide are still the same.

Close together. When returning to a slightly darker place, under the action of copper oxide catalysts, silver and halogens.

It is recombined to form silver halide, and the glass lens becomes transparent again.

Color-changing lenses are good, but they should not be worn for a long time. Because after wearing the chromochromic lens, due to the weakening of visible light, the pupil.

If the hole is enlarged for a long time, the amount of ultraviolet rays entering the eye is multiplied, which can cause damage to the eye.

Excessive UV exposure can cause corneal edema, lose its original luster and elasticity, and make the pupil less responsive to light.

decreased vision; The prolonged effects of ultraviolet rays can also lead to hardening and calcification of crystals, inducing cataracts. Other than that.

A small number of people who are allergic to ultraviolet rays can also cause fundus diseases such as central retinitis, which can seriously damage vision.

Because glaucoma patients should not work in the dark or read for too long, although the color-changing lens is exposed to natural light in the room.

The color is very light, but it still has a great impact on its vision, so glaucoma, especially those with narrow-angle glaucoma, it is best not to.

Use photochromic lenses. In addition, because the diopter is too high, the color depth of the photochromic lens is inconsistent, which will affect the clarity of vision.

Therefore, people with high myopia or high farsightedness should not wear photochromic lenses.

Color-changing glasses In bright light, the lenses turn dark brown, and when the light darkens, the lenses become almost colorless and transparent. Why do photochromic mirrors change color?

It turns out that self-tinting lenses are microcrystals of silver bromide and copper oxide added to ordinary glass. When exposed to strong light, silver bromide decomposes into silver and bromine.

The tiny grains of silver that decompose give the glass a dark brown color. When the light is dimmed, silver and bromine are catalyzed by copper oxide, regenerating silver bromide.

As a result, the color of the lenses has become lighter again.

The Principle of Tinted LensesThe mystery of tinted glasses lies in the lens. In the manufacture of the lenses, a UV-sensitive substance, silver halide, is pre-incorporated, along with a small amount of copper oxide catalyst. The change of spectacle lenses from no color to light gray and brown, and then from dark glasses back to ordinary glasses, is the "magic" of silver halide changes.

In the lens material of the photochromic lens, there is a very similar process to the imaging of photosensitive film. The silver halide decomposes into many black silver particles, which are evenly distributed in the lens, so that the lens appears dull and blocks the passage of light, which is the darkening of the color.

Unlike photosensitive film, the silver atoms and halogen atoms formed by the decomposition of silver halide are still close together. When it returns to a slightly darker place, the silver and halogen are recombined with the copper oxide catalyst to form silver halide, and the lens becomes transparent again. The speed and depth of discoloration of self-tinting lenses are related to UV intensity and ambient temperature.

Regarding the understanding of photochromic glasses, you can refer to the fact that the speed and depth of discoloration of photochromic lenses are related to the intensity of ultraviolet rays and the ambient temperature, and have little to do with the cloudiness of the weather.

Tinted lenses. The principle of the first dress mainly relies on a special chemical reaction of ultraviolet light.

The self-tinting lenses of sunglasses[1] contain certain substances (e.g., silver chloride.

or silver halides). When there is no ultraviolet radiation, visible light.

It is possible to penetrate these molecules, and visible light is a general component of artificial light sources. But when exposed to the sun's ultraviolet rays, these molecules undergo a chemical process that causes them to change their shape. The new molecular structure of the celeryl absorbs a portion of the visible light, which darkens the lens.

The number of molecules that change shape varies with the intensity of UV light.

change and change. When you go indoors, away from UV exposure, a corresponding chemical reversal change occurs. When exposed to ultraviolet light, these molecules will quickly revert to their original structure, thus losing the ability to absorb light.

Whether it's a positive or negative change, the whole process happens quickly. In the PhotoBrown and PhotoGrey series produced by Corning in the 60s, the lenses were made of glass with a uniform distribution of molecules.

throughout the lens. When this method is used in prescription glasses, the problems become apparent because the thickness of different parts of the prescription lens can vary, and the color will appear darker where it is slightly thicker. But with the growing popularity of plastic lenses, a new method has been developed.

By soaking the plastic lens in a chemical tank, the color-changing molecules will be absorbed to a depth of approximately 150 microns inside the plastic lens. This new method is significantly superior to simple coating processes, where the discoloration molecule is only 5 microns thick, which does not provide enough molecules to darken the lens. At present, Transitions, a leader in the manufacturing of photochromic lenses, has popularized this plastic lens adsorption process.

The principle of discoloration of photochromic glasses is related to the properties of silver halide. The mystery of photochromic glasses is in glass, and this special glass is called "photochromic" glass.

Color-changing glasses are glasses made of color-changing glass. A glass that changes its color when irradiated with light of the appropriate wavelength and returns to its original color when the light source is removed. Also known as photochromic glass or photochromic glass.

Chromic eyes are pre-mixed with light-sensitive substances such as silver chloride, silver bromide and a small amount of copper oxide catalyst during the manufacturing process. Spectacle lenses change from no color to light gray and brown, and then from black glasses back to ordinary glasses, all of which are "magic" of silver halide.

In the glass of photochromic glasses, there is a process of change that is very similar to that of photosensitive film. Silver halide decomposes into many black silver particles, which are evenly distributed in the glass, so that the glass lens appears dull and blocks the passage of light, which is called dark glasses.

However, unlike the situation on photosensitive film, the silver atoms and halogen atoms formed by the decomposition of silver halide are still close together, returning to a slightly darker place, and under the action of copper oxide catalyst, the silver and halogen are recombined to form silver halide, and the glass lens becomes transparent again.

Color-changing lenses are good, but they should not be worn for a long time. After wearing photochromic lenses, the pupil is dilated for a long time due to the weakening of visible light, which multiplies the amount of ultraviolet rays entering the eye, which can cause damage to the eyes.

Excessive ultraviolet radiation can cause corneal edema, lose its original luster and elasticity, make the pupil slow to respond to light, and reduce vision; The prolonged effects of ultraviolet rays can also lead to hardening and calcification of crystals, inducing cataracts. In addition, a small number of people who are allergic to ultraviolet rays may also cause fundus diseases such as central retinitis, which can seriously damage vision.

Because glaucoma patients should not work in the dark or read for too long, although the color change lens is very light in the natural light of the room, it still has a great impact on their vision, so glaucoma, especially those suffering from narrow-angle glaucoma, it is best not to use color change lenses. In addition, because the diopter is too high, the color of the photochromic lens is inconsistent, which will affect the clarity of vision, so people with high myopia or high farsightedness should not wear photochromic lenses.

According to the principle of reversible reaction of photochromatic spectacle lenses, the lenses can be rapidly darkened under sunlight and ultraviolet irradiation, completely absorb ultraviolet rays, and neutrally absorb visible light; Back in the dark, it can quickly restore colorless transparency. The photochromic properties of this lens are permanently reversible. <

According to the principle of reversible reaction of photochromatic spectacle lenses, the lenses can be rapidly darkened under sunlight and ultraviolet irradiation, completely absorb ultraviolet rays, and neutrally absorb visible light; Back in the dark, it can quickly restore colorless transparency. The photochromic properties of this lens are permanently reversible.

Color-changing glasses: Glasses made of color-changing glass.