1. The advantages of the 1.56 ①Lenses with a 1.56 index are considered the most cost effective lens on the market. They possess 100% UV protection and are 22% thinner than CR39 lenses. ②1.56 lenses can cut to fit the frames perfectly, and these lenses with knife edge finishing would suit those irregular frame sizes (small or large) and would make any pair of glasses look thinner than ordinary. ③1.56 single vision lenses have higher Abbe value, can offer wearers excellent wearing comfort.2. The advantages of the bifocal lenses ①With a bifocal, distance and near are clear but the intermediate distance (between 2 and 6 feet) is blurred. Where intermediate is essential for a patient a trifocal or varifocal is required. ②Take the instance of a piano player. He can see distance and near, but the music notes he has to read are too far away. Hence, he has to have an intermediate section to see them. ③A lady who plays cards, can see the cards in her hand but cannot see the cards laid on the table.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 |
| 1.56 flat-top semi-finished optical lens | |
| Model: | 1.56 optical lens |
| Place of Origin: | Jiangsu, China |
| Brand: | SETO |
| Lenses Material: | Resin |
| Bending | 200B/400B/600B/800B |
| Function | flat-top & semi-finished |
| Lenses Color | Clear |
| Refractive Index: | 1.56 |
| Diameter: | 70 |
| Abbe Value: | 34.7 |
| Specific Gravity: | 1.27 |
| Transmittance: | >97% |
| Coating Choice: | UC/HC/HMC |
| Coating color | Green |