Advantages of Progressive Lens
Continuous and clear vision throughout the entire process is the advantage of progressive lenses. Because the added value continuously increases gradually in the gradient zone, the wearer can obtain continuous clear vision from the far point to the near point through the gradient lens under the appropriate head position. In line with physiological optics, better adaptation. The appearance is better than that of double-lens and triple-lens. There is no dividing line of sub-sheets, and there is no ring-shaped blind zone and invisible sub-sheets.
How do you buy prescription glasses on GlassesUSA?
Fill out a form on their website to enter a prescription, choose to have them follow up and require it later, or use their prescription scanner app on an existing pair of glasses. However, the app isn't always easy to use. You'll need your phone, a computer with enabled cookies, your glasses, and a magnetic stripe card to determine the size.
Application of titanium alloy
Titanium alloy is mainly used in aircraft engine compressor parts, followed by rocket, missile, and high-speed aircraft structural parts.By the mid-1960s, titanium and its alloys were already in common industrial use, making electrodes for industrial electrolysis, condensers for power stations, heaters for petroleum refining and seawater desalination, and pollution control devices.Titanium and its alloys have become a kind of corrosion-resistant structural material.In addition, it is used to produce hydrogen storage materials and shape memory alloys.
Thin frame glasses
Curved-rimmed glasses are very popular and common nowadays. It feels serious and intellectual. It is suitable for all face shapes. There are many colors to choose from. Fairies who especially like square frames can choose thin square glasses with gold wire. The border is not too obvious but it has edges.
Discoloration time and fading time for color-changing lenses
In general, color-changing lenses take about 30 seconds to 1 minute to darken on average when exposed to sunlight/UV and will continue to darken for about 10 minutes to reach the lens depth of full-color sunglasses. Color-changing lenses of good quality and workmanship are restored to an almost clear and transparent state in 2 minutes and completely cleared in 5 minutes, although the high temperature can affect this. If you want to change a single color change lens, the color of the old and new lenses will be inconsistent. This is because the discoloration performance of the old lens will be reduced due to the long-term use of the discoloration agent. Therefore, in order to ensure the normal use and aesthetic appearance, it is usually recommended to replace the two lenses at the same time.
How to test a blue-light lens?
Look at the lens. High-quality anti-blue glasses do not interfere with the line of sight, with high transmittance. The light transmittance is very high, and the visual clarity is higher, which does not affect the visual quality, quality of life, contrast sensitivity, and color discrimination.
Important to measure pupils
The interpupillary distance refers to the distance between the centers of the two pupils when the visual axis is square and parallel. In general, the optical center of the glasses should coincide with the visual axis of the eye when looking at eye level. That is, the optical center distance of the glasses should be the same as the interpupillary distance. Otherwise, visual discomfort will occur, causing visual fatigue and deepening the degree. Therefore, we must improve consumers' awareness of self-quality protection. Understand the knowledge of glasses, otherwise, only mild myopia, the long-term wearing of unqualified glasses will cause the degree to deepen and become high myopia. So be sure to go to a regular optician to get glasses.