The difference between 1.56 mid-index and 1.50 standard lenses is thinness.
Lenses with this index reduce lens thickness by 15 percent.
Full-rim eyewear frames/glasses worn during sports activities are most suitable for this lens index.
Generally speaking, the spherical lens is thicker; the imaging through the spherical lens will deform.
The aspheric lens, is thinner and lighter, and make a more natural and realistic image.
Sunlight is made up of red, orange, yellow, green, blue, indigo and violet light. When combined, it becomes the white light we see. Each of these has a different energy and wavelength. Rays on the red end have longer wavelengths and less energy. On the other end, blue rays have shorter wavelengths and more energy. Light that looks white can have a large blue component, which can expose the eye to a higher amount of wavelength from the blue end of the spectrum.
1. Blue light is everywhere.
2. HEV light rays make the sky look blue.
3. The eye is not very good at blocking blue light.
4. Blue light exposure may increase the risk of macular degeneration.
5. Blue light contributes to digital eye strain.
6. Blue light protection may be even more important after cataract surgery.
7. Not all blue light is bad.
Blue light reducing lenses are created using a patented pigment that is added directly to the lens before the casting process. That means the blue light reducing material is part of the entire lens material, not just a tint or coating. This patented process allows blue light reducing lenses to filter a higher amount of both blue light and UV light.