Myopia is very harmful to the eyes, and many people choose to wear glasses to control the degree of myopia. However, a good pair of glasses cannot be separated from good lenses. As a professional manufacturer of eyewear making glasses manufacturing machine, we also hope that all myopic patients can have high-quality frames and high-quality lenses. So, how to choose good spectacle lenses?
How to choose good spectacle lenses?
1. Visible light transmittance. The higher the transmittance, the clearer the vision;
2. Abbe number. The larger the Abbe number, the better. The smaller the Abbe number, the greater the dispersion. The greater the dispersion, the more likely it is to produce a rainbow effect;
3. Safety. The lens should be strong and durable, not easy to break, otherwise it will hurt the eyes after the lens is broken;
4. UV protection. The stronger the UV protection, the better for the eyes;
5. Lightweight. The lighter, the less pressure on the ears and nose;
6. Refractive index. For lenses with the same degree, the larger the refractive index, the thinner the lens;
7. Chemical stability. Good chemical stability should be resistant to corrosion by external acids, alkalis, salts, air, water vapor, etc.;
8. Good wear resistance. Lenses with poor wear resistance are easily scratched and have scratches, which shortens the service life;
9. Others. Whether an anti-reflection film is added, the quality of the coating, the quality of the solid resistance, etc., all affect the evaluation of the lens.
When choosing lenses, you must choose coated lenses. Coated lenses can increase light transmittance, up to more than 99%, eliminate multiple halos caused by repeated reflections on the front and back surfaces of the lens, and eliminate ghosting caused by repeated reflections on the lens surface, making the eyes more comfortable. Coated lenses are generally added with ultraviolet absorbers to absorb ultraviolet rays to protect the eyes.
When choosing lenses, you should first understand which categories they are divided into and what are the main performance characteristics of the lenses. Among the lens performance, the focus is on the optical performance of the lens, such as light transmittance, lens refractive index, lens Abbe number, lens processing quality, lens surface treatment, etc. After knowing the above, choose lenses according to the situation and requirements.