What is a Tonopen? | KOALAEYE OPTICAL

What is a Tonopen?

What should be noticed about low bridge glasses?

At the same time, the weight of your frame should be evenly distributed across the bridge of your nose or on the nose pad of the frame. If the bridge sinks into your nose, either your nose pad needs to be adjusted better, or you need to find a frame with a wider bridge. In addition, the temple or handle of the glasses should be long enough to fit close to the ear. You should be able to move your head without slipping or slipping off your glasses. In short, for those with a lower nose, a triple match requires that the nose chassis have a thicker or adjustable nose pad, a narrower nose bridge, a wider nose bridge, and a shorter lens. If you have bought a plastic frame in the past or present, you should be able to find the size of your bridge on your current frame. Traditionally, the middle number corresponds to the measurement of the bridge. It is important to look at the position of the bridge on the frame.


What is vision insurance?

The term vision insurance is commonly used to describe health and wellness plans designed to reduce the cost of regular preventive eye care (eye exams) and prescription glasses (glasses and contact lenses). Some vision plans provide discounts on elective vision correction precesses, like LASIK and PRK. But unlike large health insurance plans, most vision plans are discount or health benefit plans that provide specific benefits and discounts on annual premiums. They can be used to cover most of the cost of eyewear, or they can be used to make high-end eyewear products and improvements, like progressive lenses, anti-reflective coatings, and photochromic lenses, which are much cheaper. Vision insurance plans usually operate differently than other health insurance plans or large medical insurance plans.



Tungsten Carbon Steel Spectacle Frame

Tungsten-carbon steel is an upgraded version of TR90. Its characteristics are basically lighter, softer, and higher in hardness than the original TR90. It is said to be the material softer than water, lighter than paper, and harder than steel. Tungsten-carbon materials are also called yellow materials in the glasses industry, and the terms of tungsten-carbon plastic are only for consumers because consumers do not know what they mean.

In terms of raw materials, titanium is the most expensive material, and the value of raw materials determines the final retail price of the glasses. The cost of tungsten carbon is slightly higher than the price of TR90 by about 20%, which is about the same as the value of low-end alloy glasses. The cost and value of pure titanium are 3 to 4 times that of TR90 and low-end alloy glasses, so the basic price difference between a pair of brand new pure titanium glasses and TR90 glasses is very large.


How to Choose Glasses for Big Heads?

In this section, we will show you how to choose an eyeglasses frame for large heads. If you do not know how to choose, keep on your reading to find some solutions.

Rectangular frames: Rectangular frames add angle and can slim down the appearance of a larger head. So, if you have a big head, try the rectangular frames glasses.

Oversized frames: if you have a big head, the oversized frames would be a good choice. Oversized glasses will balance out your larger features.

Wayfarer frames: whether your style is retro or geek chic, you will find a perfect fit in trapezoidal wayfarer. The thick angular frames offset rounder cheeks and draw attention down from the forehead. So, if you have a large head, try this style.

When choosing glasses for large heads, you should also find the right shape and color for your signature look and style. While there are a lot of glasses styles for big heads, you should consider glasses with long enough temple length, the length between the hinge of your frames and where they bend around the ear. This measurement is critical for overall comfort, especially on your temples and near your ears.

So, from the above information, you have learned how to choose glasses for big heads.



Why do you need blue-light-blocking glasses?

High-energy blue light would penetrate the lens and directly enter the retina, causing the atrophy and even death of retinal pigment epithelial cells. The death of light-sensitive cells will lead to vision loss or even complete loss, which is irreversible. Blue light at 415 nanometers to 455 nanometers is short, that is, high energy and harmful blue light. This band of blue light would penetrate the lens directly to the center of the macula, causing irreversible damage to the macula. Excessive intake of high-energy blue light would cause confusion of our biological clock, so the damage of blue light should be paid enough attention to.


How do you find the right frame at Walmart?

There are different sizes of glasses frames, and the size suitable for each person is not the same. When choosing the glasses frame, you should pay attention to the size. You can compare the size of the glasses frame by querying it, or trying it on directly. There are also many shapes of spectacle frames. Usually, people with heart-shaped faces can choose each type of glasses frame. But for other face shapes, they need to foster strengths and circumflex weaknesses when choosing.

Under normal circumstances, it is recommended that dark skin choose black, tortoiseshell color, and other colors of some dark frames. For those with a yellowish complexion, avoid wearing yellow frames. You can match the glasses that shallow bright color fasten, so the glasses that come out to wear just can appear temperamental outstanding.


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What Glasses Are Made Of?

In general, most glasses are made of plastic lenses. Why are glasses lenses made of plastic? In fact, plastic glasses are lighter than traditional glasses lenses used in eyeglasses, which means they are more comfortable to wear. At the same time, it is easy to apply lens coatings like anti-reflective to plastic lenses.

Besides, children’s glasses are also made of plastic because it is more resistant to impact. There are four main types of plastics used to make eyeglasses and sunglasses lenses which are plastic, Trivex, polycarbonate and high-index plastics.

The plastic lenses made from CR-39 were first introduced. CR-39 is an abbreviation for Columbia Resin #39, the 39th plastic of that type made by Columbia Resin.

Then the polycarbonate glasses were invented. Polycarbonate became out of this world once it found use in aeronautics. Polycarbonate is a type of plastic that can be produced as transparent and easily shaped, making it great for glasses lenses. Polycarbonate is impact resistant so that they are a good lens choice for kids. And the polycarbonate lenses have 100% UV protection.

Next, high-index lenses are available. High-index lenses have a high refractive index with a thin lens. Although high-index lenses are thinner, they are heavier due to the higher density of these plastics.

So, what glasses are made of? Most glasses are made of plastics. Then how are glasses made? To get the answer, keep on your reading.

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