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Why do we need a pair of color-changing glasses?

May 29, 2019

The color-changing lens is mainly used in the open field, snow, indoor strong light source workplace to prevent sun, ultraviolet light, glare and light damage to the eye.

What is the color-changing glasses?

Photochromic glass is a pair of glasses made of color-changing glass.


A lens that automatically produces a color change as the ambient light changes. Fully called photochromic glasses, also known as light color glasses. The color-changing lens is irradiated with ultraviolet light and short-wave visible light in sunlight, and the color becomes darker, and the light transmittance is lowered; in the indoor or dark, the light transmittance of the lens is improved, and the color fading is recovered. The photochromism of the lens is automatic and reversible. The color-changing glasses can adjust the transmittance through the discoloration of the lens, so that the human eye can adapt to changes in the ambient light, reduce visual fatigue, and protect the eyes.

Color-changing lenses, also known as "photosensitive lenses." The glass lens is added with silver halide, but the current mainstream is a resin color-changing lens. A chemical substance such as a pyrrolidine ring is added to the acrylic resin lens, so that the original transparent and colorless lens will become a colored lens when exposed to strong light. To protect, so it is suitable for indoor and outdoor use.

The color-changing lens is made of optical glass containing silver halide microcrystals. According to the principle of reversible reaction of light-color interconversion, it can be quickly darkened under sunlight and ultraviolet radiation, completely absorbs ultraviolet light, and is neutrally absorbed to visible light; Can quickly restore colorless and transparent.

The color-changing lens is mainly used in the open field, snow, indoor strong light source workplace to prevent sun, ultraviolet light, glare and light damage to the eye.

Before the discoloration of the color-changing lens, there are two kinds of base color films and one color base film; the color after discoloration is mainly gray or brown.

What are the advantages of color-changing tablets over ordinary lenses?

Ultraviolet rays "sunburn" the surface of the eye, and long-term accumulation effects directly lead to various eye diseases. For example, photokeratitis also causes a benign macula on the surface of the eye. Two other common eye diseases, pingueculae and pterygia, are triggered.

According to recent survey results, long-term exposure to ultraviolet light accumulation effects may cause serious age-related diseases in the eyes and surrounding sensitive areas, including cataracts and chloasma, which are the main causes of blindness in the elderly. According to data released by the World Health Organization, 16 million people worldwide are blinded by cataracts each year, and 20% of them are caused by long-term exposure to ultraviolet light. The harm of ultraviolet rays is extraordinary.

When the color-changing spectacle lens encounters ultraviolet rays, its coating layer will quickly deepen while blocking the invasion of ultraviolet rays, and greatly block the damage of UVA and UVB to our eyes. In the developed countries, the color-changing tablets have long been recognized by consumers with strong health awareness because of their health, convenience, beauty and other advantages. The customers of color-changing lenses grow at a double-digit rate every year.

"Whether this kind of lens is practical depends on your own use. If you go out often and feel that you are wearing two pairs of glasses (normal glasses + myopia sunglasses), then this is more convenient, it is transparent indoors, and it is dark outside. That is to not delay the daily use, but also to protect the eyes from UV damage, because the principle of discoloration of such lenses is UV light discoloration, generally discoloration is very fast, recovery is based on the degree of discoloration, usually about 2-4 minutes. ————There is also a quick color change, but the price is also very good.


How to choose?

When choosing color-changing glasses, it is mainly considered from the aspects of the functional characteristics of the lens, the use of the glasses, and the individual's requirements for color. The photochromic lens can also be made into a variety of colors, such as gray, brown, and the like.


1. gray lens: can absorb infrared rays and 98% of ultraviolet rays. The biggest advantage of gray lenses is that they don't change the original color of the scene due to the lens. The most satisfying thing is that it can effectively reduce the light intensity. The gray lens absorbs evenly on any chromatogram, so the viewing scene will only darken, but there will be no obvious color difference, showing a true natural feeling. It is a neutral color and is suitable for all people.

2. pink lenses: This is a very common color. It absorbs 95% of the UV rays. If it is used as a corrective eyeglass, it is best to use a reddish lens for the woman who must wear it frequently. Because the light red lens absorbs ultraviolet light better and reduces the overall light intensity, the wearer feels more comfortable.

3. light purple lens: like the pink lens, because of its relatively dark color, more popular with mature women.

4. brown lens: can absorb 100% of ultraviolet light, brown lens can filter a lot of blue light, can improve visual contrast and clarity, so it is popular with the wearer. Especially in the case of serious air pollution or foggy, the wearing effect is better. Generally, it can block the reflected light from the smooth and bright surface, and the wearer can still see the fine parts, which is the ideal choice for the driver. For middle-aged and elderly patients with high vision of 600 degrees or more, priority can be given.

5. light blue lens: beach blue beach play can wear sun blue lens, blue can effectively filter the light blue of sea and sky reflection. Blue lenses should be avoided when driving, as it will make us unable to distinguish the color of traffic signals.

6. green lens: green lens can be the same as the gray lens, can effectively absorb infrared light and 99% of ultraviolet light. While absorbing light, it maximizes the green light that reaches the eyes, so it has a cool and comfortable feeling, and is suitable for people who are prone to fatigue.

7. yellow lens: can absorb 100% of ultraviolet light, and can allow infrared rays and 83% of visible light to penetrate the lens. The biggest feature of yellow lenses is that they absorb most of the blue light. Because the sun shines through the atmosphere, it is mainly represented by blue light (which explains why the sky is blue). When the yellow lens absorbs blue light, it can make the natural scenery clearer. Therefore, the yellow lens is often used as a "filter" or used by hunters during hunting.

Strictly speaking, such lenses are not sunglass lenses because they hardly reduce visible light, but in foggy and dusk moments, yellow lenses can improve contrast and provide more accurate video, so they are also called night vision goggles. Some young people wear yellow lenses "sunglasses" for decorative use, glaucoma performers and patients who need to improve visual brightness.