1.The characteristics of 1.60 lens ①Thickness 1.61 lenses are thinner than the normal middle index lenses due to their ability to bend light. As they bend light more than an ordinary lens they can be made much thinner but offer the same prescription power. ②Weight 1.61 lenses are about 24% lighter than common lenses because that they can be made thinner, so they contain less lens material and are therefore much lighter than ordinary lenses. ③Impact resistance 1.61 lenses can meet FDA standard, pass the falling spere test, have higher resistance to scratches and impact ④Aspheric design 1.61 lenses can effectly reduce aberration and distortion, relieving the visual fatigue caused by oppression effectively3.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

1.60 photochromic semi-finished optical lens
Model:	1.60 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:	1.60
Diameter:	70/75
Abbe Value:	32
Specific Gravity:	1.26
Transmittance:	>97%
Coating Choice:	UC/HC/HMC
Coating color	Green

2. Why do we wear the photochormic 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 lenses