|Semi Finished 1.59 PC Blue Blcok HMC Optical Lens|
|Hard and AR coating for both lens surface, suitable for people who spend a lot working with computer, mobile phone, laptop. Tablet PC|
What is blue light?
Blue light is a form of visible light with a wavelength in the range from 380nm to 500nm. It has a very short wavelength, and so produces a higher amount of energy. Studies suggest that over time exposure to the blue end of the light spectrum could cause serious long-term damage to eyes.
Where is blue light?
Blue light is actually everywhere. Sources of blue light include the sun, digital screens (TV, computer, laptop, smart phone and tablet), electronic devices, fluorescent and LED lighting.
Semi Finished Lens
Semi-finished lens is the raw blank used to produce the most individualized RX lens according to thepatient's prescription. Different prescription powers request for different semi-finished lens types or base curves.
The semi-finished lenses are produced in a casting process. Here, liquid monomers are first poured into moulds. Various substances are added to the monomers, e.g. initiators and UV absorbers. The initiator triggers a chemical reaction that leads to hardening or "curing" of the lens, while the UV absorber increases the UV absorption of the lenses and prevents yellowing.