Compare to the glass lens, resin lens is more soft, and very easy to scratch. So it is necessary to hard the resin lens with hard liquid. Make the inner and outer surfaces of the lens have thermo-chemical and mechanical protection layer.
Resin lens with hard coat and without will have different life time. For hard coat lens it will be 5 years but the without one will be only 2 year. Another reason for lens should be hard is that, if you want other funtion for the lens, like HMC,AR,BLUE CUT and so on, the lens must have hard coat before coating other function films. That's why the lens should be hard coat.
Yuzhou Optics can provide 6H lens and 8H lens, the different is that 8H is super hard than 6H lens, and can't be tinted for other color. Yuzhou 6H lens with primer coating layer is suitable for USA market and special for FDA requirement,pass the drop ball test.
