Do Photochromic Lenses Wear Out? | KOALAEYE OPTICAL

Do Photochromic Lenses Wear Out?

What are browline frames?

The name browline comes from the design of the frame. The upper part of the frame is thicker than the lower part so that the wearer's natural eyebrow line can be noticed. The top is usually made of acetate or plastic, and the bottom of the lens is wrapped with a thinner wireframe. Later, the browline frames have also been modified to meet the needs of more customers. Some browline frames use nylon wire instead of metal wire in the lower part, while the browline frames with metal wire are more durable and stable. If people with high myopia want to have a pair of half-rim glasses, browline frames are a good choice.


What is a progressive lens?

Progressive multifocal lenses are lenses with different upper and lower powers for seeing far above and below for seeing near. The distance from the fixed far power above the lens to the near power fixed below the lens does not change suddenly, but a gradual transition between the two through the gradual change in refractive power. Compared with ordinary lenses, there are many advantages. The appearance of the lens is like a single vision lens, and the dividing line of the power change is not visible. Not only is the appearance beautiful, but more importantly, it protects the age privacy of the wearer, and there is no need to worry about revealing the age secret due to wearing glasses.

Since the change of the lens power is gradual, there will be no image jump. It is comfortable to wear and easy to adapt. So it is easy to be accepted. Because the degree is gradual, the replacement of the adjustment effect is gradually increased according to the shortening of the short distance. There is no adjustment fluctuation, and it is not easy to cause visual fatigue. Clear vision can be obtained at all distances in the visual range.

Such a pair of glasses meets the use of long-distance, near-use and various distances in the middle at the same time. It is especially good news for teachers, doctors, music workers, and computer operators, because these people not only need to see far and near objects clearly, but most of the time they also need to be able to see middle distance objects such as blackboards, piano scores, and computer screens. . This is not possible with any lens other than progressive lenses.



How To Choose Better Night Driving Glasses?

Choose and buy glasses to use a special night with anti - strong night driving lens. The demand is to block 80-90% of the strong lights and harmful lights, and at the same time to make the road more clearly. Choose glasses with thicker lenses, they are more durable and protect the eyes of drivers against irritation and accidental breakage. As common sunglasses and color-changing glasses are only suitable for daytime wear, wearing them at night will seriously affect the driver's vision.

Common light yellow night driving glasses can only block a small amount of light, and is not very suitable for night driving glasses standards. Therefore, in the choice of lenses of night driving glasses, we must do the selection and demonstration of the national authority of the formal institutions to test products, to achieve the desired effect in actual use. Don't buy products that are not up to standards from vendors. Such products not only do not block the lights but may affect the driver to see the road ahead, affecting the safety of the train operation.


What To Do with Old Glasses?

You can also choose to send your old glasses to others. You can ask your friends or ask around your social network to see if someone needs a pair of glasses. Then give them the old glasses.

If your glasses are too broken to be redistributed, do not just throw them out. You can choose to throw your old glasses into the recycle bin and they will be recycled.

If the only reason to give away your old glasses is that they are broken, you can try to repair them. After that, they can be useful.



About Non-polarized Sunglasses

Non-polarized sunglasses block only commonly strong light and filter ultraviolet rays. And the efficiency of its filter ultraviolet ray is lower. But you know, in our daily life, in addition to strong light and ultraviolet light, the light through the uneven road surface, water, and other places will also produce an irregular diffuse reflection of light, so that the human eyes will suffer blurred vision, fatigue. Generally speaking, for a short period of outdoor sports, the non-polarized sunglasses can already meet your needs.


Why are some glasses expensive and others cheap?

Lenses do not regulate vision, but some progressive lenses can help the ciliary muscles to adjust. The quality of the lens is mainly determined by the transmittance, the surface, the aspherical surface, the refractive index, the coating quality.

The higher the refractive index, the thinner the lens, and the more expensive the price, for some people with high degrees, the lenses also play an aesthetic role. Commonly used are green film, and some are purple film, gold film, etc. How much cheaper is a relative number, and there are many other factors to consider besides price.


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Testing of aspheric lens

The optical axis of the optical center just overlaps with the visual axis of the eye, which is the most ideal state. Because the light from the edge cannot form a focus on the optical axis, when the optical axis does not overlap with the visual axis (the difference is greater than 2mm), such unclear and scattered imaging results will occur. When choosing frames and aspheric lenses, you need to ensure that they fit correctly, to achieve the best visual and decorative effects. Simply put, due to the special design of the lens, we found through a calculation that the optical center should move down 1mm higher than the pupil for every 2° increase in front inclination angle. Otherwise, the wrong pupil height will cause the lens to look like astigmatism, and cause discomfort. For glasses with aspheric lenses, there must be an inclination angle after wearing. The specific angle varies from person to person.

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