1.56 Photogrey Blue Block Round Top HMC Bifocal Finished Lens

1. Photochromic Function    
The color depth can be dynamically adjusted according to the ambient light intensity, realizing "one lens with two uses" - it can become darker and serve as sunglasses in strong outdoor light, and return to transparent and serve as ordinary corrective lenses in low indoor light.    
    
2. Bifocal Design    
The edge of the circular near vision zone is a smooth arc. When switching from the distance vision zone to the near vision zone, the line of sight will not encounter a "horizontal straight line dividing line", avoiding the "image jump" (sudden discontinuity of the picture) that may occur with flat-top lenses, and the visual transition is more natural.
    
3. Blue Light Protection:    
It only filters out high-energy short-wave blue light (wavelength 415~455nm, also known as "harmful blue light") that is harmful to the eyes, while retaining low-energy long-wave blue light (wavelength 455~490nm, involved in regulating the biological clock, improving mood, etc.) that is beneficial to the human body, avoiding visual color cast and biological clock disruption caused by "full-band filtering".