1) What's the importance of a good semi-finished lens to RX production? a. High qualified rate in power accuracy and stability b. High qualified rate in cosmetics quality c. High optical features d. Good tinting effects and hard-coating/AR coating results e. Realize the maximum production capacity f. Punctual delivery Not just superficial quality, semi-finished lenses are more focus on the internal quality, such as precise and stable parameters, especially for the popular freeform lens.2）What Are Bifocal Lenses? Bifocals are two prescriptions combined into a single lens. Bifocals were originated by Benjamin Franklin in the 18th century when he cut the halves of two spectacle lenses and fitted them into one frame. Bifocals are needed because the distance glasses do not suffice to focus sufficiently for near. As age increases, reading glasses are required to read at a comfortable distance. Rather than taking out the distance glasses and putting on near glasses each time, a person who wishes to work at the near point could use the lower segment comfortably. There are various types of bifocals available, from the round-top bifocal, flat-top bifocal to the executive bifocal.
3) 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 |
| 1.499 round-top semi-finished optical lens | |
| Model: | 1.499 optical lens |
| Place of Origin: | Jiangsu, China |
| Brand: | SETO |
| Lenses Material: | Resin |
| Bending | 200B/400B/600B/800B |
| Function | round-top |
| Lenses Color | Clear |
| Refractive Index: | 1.499 |
| Diameter: | 70/65 |
| Abbe Value: | 58 |
| Specific Gravity: | 1.32 |
| Transmittance: | >97% |
| Coating Choice: | UC/HC/HMC |
| Coating color | Green |