The birth of progressive lenses
In 1907, British optometrist Owen Aves first proposed the concept of progressive lenses and got the first patent of progressive lenses. In 1910, Henry Orford Gowlland designed and made a similar lens in Canada, but technical limitations prevented it from succeeding. In 1959, Bernard Maitenaz, a French optical and mechanical engineer, developed the first progressive lens, which was successfully put into the commercial market for the first time and became a milestone in the history of world optometry. With the development of science and technology, the design of progressive lenses has been greatly developed.
Contact Lens Materials - Non-HEMA materials
The non-HEMA materials are hydrophilic soft lens material, which does not contain HEMA components. They are stronger and more oxygen permeable than most HEMA polymers.
The water content of regular hydrogel lenses varies from 30% to 58%. When oxygen passes through the hydrogel, it needs to be carried by water molecules in the material. Therefore, the higher the water content of the lens, the higher the oxygen permeability value. The softer the lens, the more comfortable it is to wear, which is conducive to the metabolism of the cornea. However, at the same time, the higher the water content of the lens, the faster the water evaporation, easy to dehydration, and easy to cause dry eyes. A lens with high water content has low material density, poor durability, and easy breakage, so they are suitable for making lenses that are frequently changed or discarded. On the contrary, the lens with low water content has good formability, easy operation, durability, and is not easy to dehydrate and cause dry eyes.
Difference Between Driving Glasses And Night Vision Goggles
Polarized glasses are made according to the principle of the polarization of light. Night vision goggles are an auxiliary observation tool based on night vision technology with the help of photoelectric imagers. Driving glasses are made according to the lens polarized angle and radian, on the basis of the principle of precision optical design. They can only make good light pass through, and other light sources, like the strong sunlight, the glare of a light source like a car headlight is filtered, thus removing the interference of external light, to avoid the presbyopia, dazzling, and so on. Night-vision goggles are divided into two kinds: One is Night Goggles, and the other one is Thermal Goggles. Image intensifying night vision technology is a photoelectric imaging technology that enhances the faint target image illuminated by night skylight through night-vision goggles with an intensifier tube for observation.
Zenni Optical is a company that sells eyeglasses online. Its mission is to provide stylish eyewear at affordable prices online. Zenni Optical sells prescription glasses, blue light glasses, and sunglasses, with a variety of lenses to choose from. You can order Zenni Optical glasses by selecting frames, lenses, and add-ons from the company's website. Zenni glasses range in price from $6.95 to $49.95. If you have a complicated prescription or add extra costs, the cost will rise to $100 or more.
Is Anti Glare Worth It?
Is anti glare worth it? To answer this question, you need to know the benefits of the anti glare glasses first. Anti reflective coating and anti glare coating offer many benefits and are definitely worth the extra cost, especially if you find yourself bothered by glare. They can help you see better, look better and feel better.
Here, we will list some of the benefits of the anti reflective coating.
- They can improve your vision by reducing bothersome reflections and glare.
- They can also provide comfort during prolonged computer use as the glasses for computer use.
- They improve visual acuity by allowing more light to reach your eyes.
- They can reduce the effect and symptoms of digital eye strain.
- They make your eyes more visible behind your lenses.
- They provide less glare when driving at night.
So, is anti glare worth it? From the above information, you can find that anti glare glasses or anti reflective glasses are worth the cost.
How to choose the right glasses for myopia?
Nowadays, people are nearsighted, and they usually think of going with a pair of glasses. However, only from the media, we continue to see that there are substandard myopia glasses and frames in the report, so how should we choose when we buy glasses? How can I match a pair of suitable and high-quality glasses? Different glasses shops vary greatly from optics technology to the quality of lens frames, so different shops have different prices. Faced with a variety of glasses, how should we choose? Generally, we can look at these four standards. First, take a look at whether the eyewear company has obtained a production license for eyewear products. Second, see if the optometry equipment and testing instruments of the glasses companies have qualified marks. Third, see if the optometry and production staff are certified to work. Forth, look at whether the glasses have a conformity mark (certificate). The four certificates of eyewear companies are the prerequisite to ensure the quality of glasses.
What is the progressive multifocal lens?
The lens of progressive multifocal glasses can change the refraction of the lens at the upper part of the central channel of the line of sight, which can effectively solve the difference of refraction when people view objects at different distances from long, medium, and short distances. Depending on demand, people have the flexibility to change or compensate vision according to visual distance, making it easier to help to adjust your vision in a variety of situations.