What Are the Advantages of Progressive Lenses?
We have shown what the progressive lenses are in the above part. Do you know what the advantages of progressive lenses are？.
1. Only need a pair of eyeglasses. As mentioned in the above section, with progressive lenses, you just need a pair of eyeglasses and there is no need for you to change different glasses constantly.
2. No unsightly bifocal line. Progressive lenses come with the multifocal lens without a multifocal line. And there is a smooth shift in lens strength, you don’t have to deal with any sudden changes in clarity.
3. More comfortable. Due to no visible line, you might feel more comfortable with a progressive lens.
What are NXT Lenses?
NXT lenses are made of Trivex materials. Trivex (Chinese name: Ethyl Carbamate Polymer) was invented by PPG in 2001.
Impact resistance:
Impact resistance is the main feature of the NXT lens. As a visual armor material originally used in the military field, Trivex has effective impact protection to the eye when it is most demanded. It is 10 times stronger than PC lenses in impact resistance and will last for life under normal use. It is the only explosion-proof safety lens on the market that can withstand external forces and turns.
Patented color injection technology :
Color representation is another important feature of NXT lenses. The biggest defect of the regular lens in dyeing is color aberration. The same color of the lens with different luminosity will produce different effects. The higher the refractive index, the serious the error. NXT lenses are a breakthrough in this respect. The patented color injection technology that infuses the color into the raw material gives the lens a natural color, ensuring that color aberrations are minimized and that they do not fade or change color over time or over long periods of use like other materials.
Abbe number and internal stress:
The Abbe number of NXT lenses made of Trivex is 43~45, which is close to CR39(58) and higher than PC lenses (29~32) and high folding lenses (32~41). At the same time, because the NXT lens is produced by the casting process, there is no stress in the finished lens, which further reduces the rainbow phenomenon, providing a guarantee for the clear visual effect and reducing eye fatigue.
Weight:
The specific gravity of NXT lens is 1.11g/cm3, 16% lighter than CR39 (1.32g/cm3) and 10% lighter than PC tablet (1.22g/cm3). The Trivex 1.53NXT medium-fold lens is so light that it can float.
Distinguish true and false myopia firstly.
Children's eyesight is not good for many reasons, excluding organic reasons. Hyperopia, myopia, astigmatism, and other refractive error factors can cause. False myopia, called modulatory myopia on medicine, is caused as a result of eye ciliary muscle overregulation. False myopia is in ciliary muscle paralysis, and the degrees disappear after putting pupil to remove adjustment.
Polycarbonate vs Plastic Lenses: Which One Is Better?
From the above information, you may have learned some features of polycarbonate glasses and plastic lenses. So, do you know which one is better?
Here are some a few differences between both lenses to determine which one is better.
- Polycarbonate lenses are more expensive than plastic glasses.
- Polycarbonate lenses are very resistant to tint compared with plastic lenses which accept tints.
- Polycarbonate glasses have inherent UV protection, while plastic lenses do not have.
- Polycarbonate glasses have higher impact resistance and offer greater protection than plastic lenses.
- Polycarbonate glasses are lighter than plastic glasses.
- Plastic glasses have a higher optical clarity than polycarbonate lenses.
So, from the above part, you may have learned which one is better and you may have a decision of how to choose.
What is the cheapest way to buy prescription glasses?
After the examination, you will bring your optometry sheet and go to the optician to match your glasses. Note that the optical shop has professional qualifications. The refractive index of the resin lens, such as 1.49, 1.56, 1.61, 1.67, and so on, mainly depends on the degree. If the degree is not high, 1.56 will do. In addition, the sophisticated store will also measure the nose height, nose width, the distance between the eyes and ears, and the forward angle of the frame, which are also indicators of whether the glasses are comfortable to wear. It is recommended to try them on after they are fitted, and the time to try on them should be longer, so as to determine whether the glasses are suitable.
What is the best lens material?
Early lenses were made of natural materials because they were easy to get. But natural materials have obvious drawbacks. According to records of the Qing Dynasty, Emperor Yongzheng wore crystal glasses given by the imperial court, which greatly improved the efficiency of reading documents. However, because of the cold nature, the crystal will make the temperature around the eyes low when wearing, and part of the crystal lens has color so that the light into the eyes becomes soft.
Confirm the optometric data
It is necessary to confirm the accuracy of optometric data. If you stay up late or look at the phone or computer for too long before the optometry, leading to visual fatigue, it will increase the degree. But if you can let your eyes have a good rest, and then take optometry, the degree may be restored to the original situation, so you need to know the state of optometry, to check if it really had increased in degrees. The main purpose of progressive lens is to use it for people who have bleached eyes and often take off the lens.
