How long do photochromic lenses last? | KOALAEYE OPTICAL

How long do photochromic lenses last?

What Do the Numbers on Glasses Mean?

The first number on glasses frames is the eye size. It is the horizontal width of the lenses. In general, the number of eye sizes varies from 40 mm to 62 mm in most of the spectacle frames.

The second number is the bridge size. It is the distance between the lenses. Also, it is the bridge that rests upon your nose. Mostly, the size of the bridge on glasses frames would be from 14 mm to 24 mm.

The third number is the temple length. It is the length of the stems of the frame that rests upon your ears. It can be measured from hinge to the end tip of the temple. In general, the temple length in most cases is from 120 mm to 150 mm. The bridge and temple help the frame to comfortably fit on the face.

Meanwhile, if there are no numbers on glasses frames, do not worry. You can always measure your eyeglasses frame with a millimeter ruler. Sometimes, the tiny numbers are worn off or sometimes they are printed too small that you might have to use the magnifying glasses. If you have known the glasses numbers meaning, you can choose to measure them by yourself.

At the same time, to fit the glasses better, you can also choose to measure your face for glasses frames. After knowing the suitable size of glasses, you can choose to buy a pair of glasses online. Thus, Koalaeye Optical is recommended. It is an online glasses store and provides all kinds of glasses, sunglasses, and frames. What’s more, these glasses are stylish and cheap.


The sporty style

Sporty style frames are a little cool, full of vitality, well-designed. They pay attention to every detail, with publicity but not exaggerated feelings. With good material, they effectively prevent collision injury to your eyes in the process of movement, greatly improving safety. The style is simple and smooth, and the appearance is dynamic and fashionable, and the color collocation is diversified. With the integration of four progressive technology to better protect your eyes, they are your outdoor leisure tourism sports choice.



Is there any relation between lens refractive index and lens definition?

First of all, in reality, from the point of view of the immediate situation, there seems to be no correlation. The refractive index is mainly related to the speed of light transmission into the lens. High refractive index lenses can be made thinner, lighter, and the technology required to do this is more sophisticated, so high refractive index lenses are more expensive. But does a high refractive index make the lens clearer? The higher the refractive index of the lens, the lower the Abbe number. The Abbe number is a very important parameter we use to measure the sharpness of the lens, which means that if the refractive index of the lens is high, that is to say, the sharpness of the lens is lower. If you have higher degrees, you can prioritize thinness and choose a lens with a higher refractive index, but don't overdo it.


What To Do with Old Glasses?

What to do with old glasses? Where can I donate old glasses? You may have the same troubles. So, in this section, we will show you what you should do with your old glasses.

You can choose to donate your old glasses. Around the world, about 13 million children can’t finish their education for the sole reason that they can’t see well enough to learn. In addition, there are some goodwill organizations that will take your used reading glasses as long as they are in decent shape. So, what to do with old glasses, donate them. Where can I donate old glasses? You can search the old glasses donation organizations online.

If you have a pair of old glasses, you can also choose to sell them online to save some money. You can sell them on some platforms such as eBay or Preloved.



How to Choose Glasses for Heart Shaped Face?

Wearing a great pair of glasses can make you look more beautiful and fashionable. You want to find a pair of eyewear to correct your vision. Of course, they should be comfortable to wear.

Everyone has their unique style. So, finding a pair of great sunglasses is not an easy job. So, in this post, we will show you some suggestions to glasses for heart shaped faces.

Before proceeding with how to choose glasses for heart shaped face, you need to know whether you have a shaped face. Heart shaped face has some obvious features, such as a broad forehead; high, prominent cheekbones; a narrow jawline; and an angular chin. So, you can check whether you have these features.

However, if you do not know what face shape you have, you can click here to take a reference and have a check.

After checking the face shape you have, we will show you some glasses for heart shaped face.


What Is Anti-Reflective Coating?

Anti-reflective coating, also known as AR, anti-glare, no-glare, or glare-free coating, can provide benefits to your vision. Anti-reflective coating is added to lenses to reduce glare caused by light hitting the back of the lenses.

Anti-reflective coating is designed to eliminate all reflections from the front and back surfaces of your lenses. Without bothersome reflections, more light is able to pass through your lenses which optimizes your vision. So, anti-reflective lenses can improve vision and make your eyeglasses more visually attractive.


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What's the use of color-changing lenses?

Photochromic lenses are lenses that are transparent indoors (not unlike our usual lenses) but darken when exposed to ultraviolet light. When no longer exposed to ultraviolet light, the lens will return to its original transparent state under the influence of ambient temperature. Color-changing lenses provide UV protection. It can provide adequate eye health protection, reducing exposure to sunlight. And it can reduce the risk of cataracts or other eye diseases. People who wear glasses, only need to have one pair of glasses indoors and outdoors in the sun, and they do not need to change glasses frequently.

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