The single vision photochromic lens is also called the "photosensitive lens". According to the principle of reversible light and color interaction, the lens can quickly darken under the irradiation of light and ultraviolet rays, block strong light and absorb ultraviolet rays, and have a neutral absorption to visible light; back to the dark place, it can quickly return to a colorless and transparent state, ensuring the lens Light transmittance. So what are its characteristics? Let’s take a look at it with the editor below!
1. Discoloration speed
The speed of discoloration is an important reference factor for the purchase of single vision photochromic lens. The faster the discoloration speed of the lens, the better, for example, from a dark room to a bright outdoor room, the discoloration speed is fast, in order to prevent the damage to the eyes from strong light/ultraviolet rays in time. Generally speaking, the film color changing technology is faster than the substrate color changing technology. For example, the new film color technology, the photochromic factor uses spiropyran compounds, which have better light responsiveness, and use the inverted opening and closing of the molecular structure itself to achieve the effect of passing or blocking light, so Faster in changing color speed.
2. Discoloration uniformity
Discoloration uniformity refers to the uniformity of the color of the lens during the process of changing the color of the lens from light to dark or from dark to light. The more uniform the discoloration, the better the single vision photochromic lens. In the traditional single vision photochromic lens, the photochromic factor is on the lens substrate, and the color change effect will be affected by the thickness of different areas of the lens. Because the middle of the lens is thin and the surroundings are thick, the middle area of ​​the lens discolors more slowly than the surroundings, and the panda eye effect will appear. The single vision photochromic lens film layer uses high-speed spin coating technology, and the color-changing film layer is uniformly spin-coated to make the color more uniform after the color change.