2）Temperature And Its Effect On Photochromic Technology The molecules in photochromic technology work by reacting to UV light. However, temperature can have an effect on the reaction time of the molecules. When the lenses become cold the molecules begin to move slowly. This means that it will take somewhat longer for the lenses to adapt from dark to clear. When the lenses become warm the molecules speed up and become more reactive. This means that they will fade back faster. It can also mean that if you’re outside on a hot sunny day, but sitting in the shade, your lenses will be quicker to detect the diminished UV rays and lighten in color. Whereas, if you are outside on a sunny day in a cold climate, and then move into the shade, your lenses will adjust more slowly than they would in a warm climate. 3）The Benifit Of Wearing Photochromic Glass  Wearing eyeglasses can often be a pain. If it's raining, you're wiping water off the lenses, if it's humid, the lenses mist up; and if it's sunny, you don't know whether to wear your normal glasses or your shades and you may have to keeping switching between the two! Many people who wear eyeglasses have found a solution to the last of these problems by changing over to photochromic lenses1）What is photochromic lens？ Photochromic lenses are also known as “photosensitive lenses”. According to the principle of reversible reaction of light color alternation, the lens can quickly darken under light and ultraviolet radiation, block strong light and absorb ultraviolet light, and show neutral absorption to visible light. Back to dark, can quickly restore colorless transparent state, ensure the lens transmittance. So the color changing lens is suitable for indoor and outdoor use at the same time, to prevent sunlight, ultraviolet light, glare on the eye damage.Photochromic lenses are also known as “photosensitive lenses”. According to the principle of reversible reaction of light color alternation, the lens can quickly darken under light and ultraviolet radiation, block strong light and absorb ultraviolet light, and show neutral absorption to visible light. Back to dark, can quickly restore colorless transparent state, ensure the lens transmittance. So the color changing lens is suitable for indoor and outdoor use at the same time, to prevent sunlight, ultraviolet light, glare on the eye damage.  4） What is the difference between HC, HMC and SHC？

Hard coating	AR coating/Hard multi coating	Super hydrophobic coating
makes the uncoated lens hard and increases the abrasion resistance	increases the transmittance of the lens and reduces surface reflections	makes the lens waterproof, antistatic, anti slip and oil resistance

1.67 photochromic semi-finished optical lens
Model:	1.67 optical lens
Place of Origin:	Jiangsu, China
Brand:	SETO
Lenses Material:	Resin
Bending	50B/200B/400B/600B/800B
Function	photochromic & semi-finished
Lenses Color	Clear
Refractive Index:	1.67
Diameter:	70/75
Abbe Value:	32
Specific Gravity:	1.35
Transmittance:	>97%
Coating Choice:	UC/HC/HMC
Coating color	Green