Disadvantages of glasses
They can distort vision, especially at the edges of lenses if you have strong prescriptions or astigmatism. Some people have trouble adjusting to progressive lenses. These lenses fog up and splash in the rain. Due to the limitation of the frame itself and the effect of the prism effect in the peripheral part of the glasses, the wearer can see a relatively narrow field of vision.
Are progressive lenses good for driving?
Progressive lenses can help you see close, far, and anywhere in between. That means progressive lenses are good for driving. So you don't have to change your glasses on the way. With progressive lenses, you can easily see all distances. Standard lenses are more affordable than premium lenses, but premium lenses offer a wider field of view and are ideal for drivers.
Why should children be more vigilant about harmful blue lights?
The amount of light transmitted to the retina through media such as the cornea, lens, and vitreous is age-related. Blue light poses the greatest risk and damage to the eyes during adolescence. As our eyes' refractive media naturally yellows, more blue light is absorbed, preventing it from reaching the retina. The lens transmittance of children under the age of 10 is more than six times higher than that of adults. It is important to prevent the damage of blue light to children's visual health.
Shorter lens beam
When you choose a glasses frame for kids, you must pay attention to that the lens beam must be short. The size of the lens beam stipulated by the national standard is 13~22mm. As a child, it should be controlled under 18mm. Otherwise, the position stability of the glasses will be poor.
Finally, they can not casually wear other people's glasses. The strength of each person's glasses, the distance between the optical centers of the two lenses, the length of the temple are different. So they can not casually wear other people's glasses.
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.
The price of new lenses
The price of the new lenses depends on several factors, including if you have vision insurance. Another aspect to think about is that if your lenses need an anti-glare solution. If so, the lenses may be much more expensive. If you need eye exams and special lenses, the cost can be quite high. Scratched lenses are easier to repair. If you want your scratched lenses repaired by a professional, most opticians can pay very little.
Single Vision vs Progressive: What Are Their Differences
With single vision lenses, you can also just use the center of the lenses to avoid prismatic effects if your prescriptions are very unequal for both eyes.
As for progressive vs single vision, they also have differences in frame selection. You will stick to frames when choosing progressive lenses that will provide you with a minimum height of 14mm from the point you are looking through the lenses into the distance to the point you are looking down while you read.
Besides the above differences, they are also some other differences between single vision glasses and progressive lenses. You can choose either one based on your needs. To choose glasses, Koalaeye glasses are recommended. They come in stylish and at a cheap price.
