Glasses are frequently replaced.
In the United States today, there are more glasses than people. Counting prescription glasses, sunglasses, and over-the-counter readers, there are now more than 400 million pairs on the market. According to the Vision Council, an industry group, they swap out a brand new pair of glasses every two years on average.
Features of progressive lenses
With the proper head position, the wearer can have a clear and continuous vision at all distances from the distal point to myopia through the progressive lens. When the eye moves from one area of vision to another, the eye adjustment process is natural and smooth, without any visual fluctuations. With natural vision and better adaptability, it is in line with physiological optics. The mid and near vision area is relatively small: Some wearers may feel that the gradient area of the progressive lens is smaller, which limits the width of the saccadic eye and requires increased head movement in order to achieve the same reading range. At medium and short distances, the wearer needs to coordinate certain head movements.
Select qualified optical lenses.
Anti-blue light lens must be qualified optical lens first and must have a certain percentage of anti-blue light effect. The general anti-blue light optical lens effect is about 30%. Even if it is not nearsighted people, it is best to choose the brand lens of reliable optical lens production enterprises. Anti-blue light lens is only suitable for people who use electronic display devices such as computers for a long time and is not suitable for patients with visual fatigue symptoms.
How can I measure the frame size?
Use a ruler to measure the glasses you used to wear comfortably and record the width of the frame and the total width in front of the frame. And compared with the frame width of the selected frame and the total front width of the frame. Frame width size difference of one or two millimeters does not matter, and the total front width of four millimeters does not matter. You can use a ruler to measure the approximate distance between the temples. Usually, the width of the inner side of the frame is the same as the temple value or about 3MM larger than the temple value.
What is the best lens material?
Trivex is a special material from PPG. Compared with PC lenses, the refractive index is lower (only 1.53) but the Abbe number is higher (up to 45), which results in smaller dispersion and better image quality. At the same time, the impact resistance of the Trivex lens is 10 times higher than that of the PC. It is the only explosion-proof safety lens that can withstand external force twists and turns in the market at present.
How To Choose Better Night Driving Glasses?
Driving at night has a high accident rate because of poor visibility, blinding headlights, and fatigue. Now the market exists a few main glasses: sunglasses polarizing lenses, Glasses that use or mimic the first generation of patented technology. So how do you compare the options between driving and wearing glasses?
Night driving lens is relatively special compared with daily driving lens, not only to prevent strong light and see the road more clearly. According to the national motor vehicle driver special glasses standards, QBT 2659-2004 daily light transmittance should be more than 8%, night light transmittance should be more than 75%. Be sure to consult customer service. Ask about the situation. Note that a pair of polarized sunglasses are not suitable for use at night, and the light transmittance must reach the national safety standards.
How to measure pupil distance?
You can ask your optometrist for this data, or if you have an extra pair of glasses, please send it to the merchant with your printed order and they will record your pupil distance value from it to ensure that your lenses have an accurate vision center. They will send you your new and old glasses together. The average pupil distance for adults is usually between 60mm and 66mm.
