How to buy contact lenses online?
Choose the right contact lens for your situation. Base arc and degree need to be added in the hospital or optician shop to determine. Try not to buy according to the framed degree. Some businesses claim to have the lenses having South Korea's silicone hydrogel, with annual throwing. They are not to be believed, because the material characteristics of the silicon hydrogel are not capable of making long-time discarded type lenses. There are a lot of things to pay attention to in order to properly wear contact lenses. For example, a medical optometry sheet is the premise of attention. Each pair of contact lenses is marked on the package of the basic arc, diameter, water content, diopter, and other parameters. Only according to the optometry sheet, you can choose the correct basic arc, diameter, and diopter. At the same time, there is a certain distance between the glasses and the cornea.
Why are titanium glasses expensive?
One reason is that the current titanium raw material cost is too high. The other reason is that the production of titanium frames is very complex. The production of titanium glasses requires special processing equipment, special welding technology, and electroplating technology, and many difficult and different processes, so it has a high production cost.
With the emergence of new titanium glasses production equipment and the improvement of production and processing technology in the industry, the price of titanium glasses will become lower and be available to a wider range of people.
What Are Progressive Lenses?
Progressive lenses are designed for people who are over 40 years old. It is a blended multi-focal lens with distance correction at the top, intermediate in the middle, and reading at the bottom. The goal is for the lens to work how your eye naturally works to let you see things both close up and far away.
Progressive lenses are made with an hourglass shape so there is some blurriness on the outer edges, but since it gives you your full range of vision, it is generally better than a bifocal despite being similar.
Difference Between Sunglasses and Optical Frame Glasses
Sunglasses are basically applied to block sunlight and adornment effect. But in the choice of lens material and lens craft respect, it is not very particular. Correspondingly, consumer wears for a fixed number of years, to be in one season or two seasons. Sunglasses are sold with obvious seasonality. Optical glasses are mainly suitable for the use of photometric glasses. Both the lens material and the production process have higher requirements. A panchromatic or half chromatic resin lens is added to an optical lens, and then they can be sunglasses and can try luminosity, made of myopic sunglasses.
Pay attention to the purchase of driving glasses.
A few points need to be kept in mind to avoid the risk of accidents. The frame should not exceed the size, because the researchers say the lens color should be gray or brown, so you can choose the aviator sunglasses, compared to other series. Aviator Sunglasses are always classic. There are plenty of cool experimental design glasses to choose from every year on the market. The selection of polarizing mirrors can filter the scattered light in the beam, remove stray light so that the light can be reflected into the eye from the right direction of the optical axis. The field of vision is clear natural. Light is adjusted in the same direction as light and reflects into the room, so the natural scenery looks soft and not dazzling, especially when driving a car or doing outdoor activities. It will affect the judgment of the object and cause danger, what’s more, long-term direct stimulation by the sun will lead to the decline of vision, the formation of myopia, hyperopia, astigmatism, or cataract.
Different Types of Eyeglass Frame Materials
Titanium: as for metal frame material, Titanium is one of the most popular ones. The titanium frame material can be bent and twisted and then come back to its original form. The quality of these frames is durable and reliable for rough use. The Titanium frame material is light.
Flexon: Flexon is a titanium alloy that is composed of around 50% titanium and 50% nickel. Flexon eyeglass frames are extremely flexible and can be twisted or bent to an extreme and can return to their original shape. The flexon frame material is popular among kids' glasses.
Beta titanium: this is an alloy mainly composed of titanium and a small amount of aluminum and vanadium. The beta-titanium has a memory feature and is mostly used in high-quality designer frames. The beta-titanium is toughness and light.
Monel: it is an alloy of nickel and copper. The monel frame material is cheap and discolor.
Beryllium: it is an alternative to titanium resisting corrosion and tarnishing, but it is cheap. The beryllium frame material is lightweight, strong, flexible and available in a wide range of colors. In addition, it is a good choice for those people with high skin acidity or those people who spend a large amount of time in or around salt water.
Besides the above plastic eyeglass frame materials and metal frame materials, there are some other frame materials available, such as aluminum, gold, silver or other biodegradables materials. You can choose the suitable one according to its performance, features, and price.
Frame Selection of Progressive Sunglasses
Choose a proper frame range. Only if the frame is not very large and beveled, the frame can be very flat. Because the distance from the glazed to the optical center of a progressive multi-focus lens is 19-17 mm, and the distance between the edges of the frame will be no less than 28 mm if the area inside the lens can be used at close range while maintaining the far sighting field.