How to Choose Good Reading Glasses
Don’t buy too cheap reading glasses for your parents. Don’t think that the cheaper the better. Cheap products are only available in the wholesale market. Such glasses have not undergone formal optometry procedures at all. Most of them are computer refractors and manuals. The insert is measured, and the processed glasses do not meet the national standards. Parents often wear such glasses, which can easily cause diplopia, eye swelling, headaches, and decreased vision. In severe cases, it may cause blindness.
1. Reading glasses selection:
When choosing reading glasses, in addition to taking price and beauty as the standard, special attention should be paid to matching the size of the selected spectacle frame with the interpupillary distance as much as possible, because it directly affects the internal optical quality and wearing comfort of the spectacles.
To identify the quality of the frame, the following can be considered:
1. Frames with good elasticity are generally of good quality.
2. The quality of the frame with smooth and shiny coating is better.
3. The quality of the frame made of smooth, small and uniform materials is better.
4. It is better to assemble all parts tightly.
5. The size and shape of the lens ring must be exactly the same and good quality
6. Material selection It is recommended to buy metal materials for reading glasses frames. The metal materials used for glasses frames are copper alloy, nickel alloy and precious metals. It is required to have a certain degree of hardness, softness, elasticity, abrasion resistance, corrosion resistance, light weight, luster and good color.
2. Reading glasses lens selection:
It is best to use resin for the lenses of reading glasses. This material can effectively resist the function of ultraviolet and infrared rays. When wearing it, it will also have a certain degree of fatigue resistance to your eyes, otherwise it will be after a while. It produces a certain sense of fatigue, and even if the quality is not good, other diseases may occur. In the end, there is no way to treat it. Therefore, the resin lens is much better than ordinary lenses. The refractive index of this kind of lens is also quite high.
The identification of lens quality can mainly consider the following:
1. Light. Generally, the resin lens is 0.83-1.5, while the optical glass is 2.27-5.95. It is recommended that the resin lens is the most suitable.
2. Strong impact resistance. The impact resistance of the resin lens is generally 8-10kg/cm2, which is several times that of glass, so it is not easy to break, safe and durable.
3. Good light transmittance. In the visible light region, the light transmittance of the resin lens is similar to that of glass; the infrared light region is slightly higher than that of glass; in the ultraviolet region, the light transmittance decreases with the decrease of wavelength starting from 0.4um, and the light with wavelength less than 0.3um is almost all absorb.
4. It can meet special needs. For example, the production of aspherical lenses is not difficult, while glass lenses are difficult to do.
5. In order to increase the permeability, the resin lenses of some famous brands of reading glasses will add a layer of anti-reflection film on the surface of the lens, which is also waterproof and anti-fouling, so the price will be slightly higher.
