SETO 1.56 Semi-Finished Flat Top Bifocal Lens

Short Description:

Flat-top lenses were used to correct two different eye prescriptions. Bifocals were easy to spot – they had a line dividing the lens in two, with the upper half for distance vision, and the lower half for reading. 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.

Tags: 1.56 resin lens,1.56 semi-finished lens,1.56 flat-top lens

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Product Detail

Product Tags

Specification

SETO 1.56 Semi-Finished Flat Top Bifocal Lens3

SETO 1.56 Semi-Finished Flat Top Bifocal Lens

SETO 1.56 Semi-Finished Flat Top Bifocal Lens2

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

Product Features

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.

3. What's the importance of a good semi-finished lens to RX production?

①High qualified rate in power accuracy and stability
② High qualified rate in cosmetics quality
③High optical features
④ Good tinting effects and hard-coating/AR coating results
⑤Realize the maximum production capacity
⑥Punctual 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.

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