What effect does a lens with the hard film have?
In order to improve the wear resistance of the lens, it is necessary to coat the surface of the lens with hard film. At present, silicon atoms are used to stiffen the membrane, that is, the stiffening solution containing organic matrix and inorganic superfine particles including silicon element is used to make the hard film have toughness and hardness at the same time. Because the common resin lens is far easier to wear than the glass lens, so the addition of hard film is mainly used for resin lens. It is usually applied to the front surface of the lens, and the anti-wear ability of the resin lens with the film will be enhanced a lot, and the light permeability will be strengthened.
Disadvantages of polarized sunglasses
Polarized sunglasses have many benefits. However, in some cases, non-polarized lenses are a safer choice. On cloudy days, drivers find that non-polarized sunglasses are better than polarized sunglasses due to the lack of glare and extreme sunlight.
Driving with polarized lenses after snowing can be dangerous for drivers. As the glare of polarized sunglasses is blocked, ice or snow on the road will not be visible. In this case, the advantages of polarized sunglasses will become the disadvantages that may cause accidents.
In addition, when driving along a dark road with few street lights at night, wearing polarized lenses will make it harder to see the road conditions because they dim the available light better than non-polarized glasses. Of course, in low-light conditions, it is best to avoid wearing sunglasses completely while driving.
The most significant disadvantage of polarized sunglasses is that they do not perform well on digital screens and displays. They can cause the images and information on the LCD screen to blur or disappear at certain angles. Don’t wear polarized sunglasses to use these devices while driving.
Rimless Reading Glasses Lightweight Readers For Women And Men [2.50]
The frames are made of high-quality materials. They use rimless and carefully designed rectangular lenses. FIORE provides the ultimate style, clarity, and comfort. Suitable for both men and women, it is characterized by lightweight and high comfort. A flexible arm and adjustable nose pad ensure comfort. It comes with a matching hard plastic case and buckle, a set of 3-in-1 hex nuts, and a screwdriver. It is the perfect gift for parents and the elderly. The best choice for Valentine's Day, Christmas, Mother's Day, Father's Day.
Contact Lens Materials - Nesofilcon A and Omafilcon A
Nesofilcon A is super water glue. This is the proprietary material of Bausch & Lomb and is now used in only one product, the Bausch & Lomb Pure Suncast (launched in the US in 2012). Water content is 78%, and the oxygen permeability is DK/T =42.
Through PC Technology, the Omafilcon A material contains substances that mimic the composition of cell membranes--- including human eyeball cells, and locks water, and prevents dryness.
The frame of prescription glasses
At present, the more common materials for frames are non-metal and metal. Non-metals mainly include TR90, sheet material, etc., and metals include alloys, titanium, and so on. TR90 and sheet material are actually plastics, but they are firm and are not easy be deformed at room temperature. Also, they have good formability so that they can be made in many fashionable styles. The general alloy material has good firmness and flexibility, but the disadvantage is that it is easy to fade. The pure titanium frame is corrosion-resistant and very strong. It is about 40% lighter than the general alloy frame. It must be welded and electroplated in an oxygen-free state, which requires high equipment and technology. Relatively speaking, the price of TR90 and alloys will be lower, and pure titanium will be more expensive. You can choose according to your budget.
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.
How to Test Computer Glasses (Clear Glasses)
First, we will show you how to test computer glasses with clear glasses.
1. Ask for Blue Light Glasses Brand Spectrum Report
To find out whether your blue light glasses are the best computer glasses, you should contact the company you bought them from and ask for a spectrum report. It will show you how much blue light your computer glasses can block.
After sending the spectrum report to you, you should make sure that your computer glasses are able to filter at least 30% blue light, otherwise, they are unsafe.
2. Use the Lens Reflection Test
As for how to test computer glasses, you can use the lens reflection test. You can see what color the light is that reflecting off the lenses.
If it reflects the blue light, they are filtering some blue light. If the reflection is violent or purple, the computer glasses may be not effective.
This is a good way for you to perform a blue light test at home.
