SF CR39 1.499 Uncoated Round Top Semi Finished Lens Blanks In Bifocal Lens Optical Lenses
I. Technical Data:
| 1.499 S/F ROUND TOP BIFOCAL BLANKS |
| MARTERIAL REFRACTIVE INDEX=1.499 TOOLING INDEX=1.530 |
| Diameter(mm) | Nominal
Curve | Front
Radius | T.C | Back
Radius | BACK
T.C | CT/ET | Frong sag
Ring 50mm | RX Range
Recommended |
| ɸ70 | 200B | 260.199 | 2.04 | 94.93 | 5.58 | 10.0/14.0 | 1.20 | -4.25Dto-8.00D |
| ɸ70 | 400B | 127.62 | 4.15 | 94.93 | 5.58 | 6.0/8.0 | 2.47 | +2.00Dto-4.00 |
| ɸ70 | 600B | 87.18 | 6.08 | 161.04 | 3.29 | 9.0/6.0 | 3.66 | 0.00Dto+4.00D |
| ɸ70 | 800B | 66.49 | 7.97 | 161.04 | 3.29 | 13.0/6.0 | 4.88 | -4.25Dto+6.00D |
II. What is the semi finished lens?
The starting point for freeform production is a semi-finished lens, also known as a puck due to its resemblance to an ice hockey puck. These are produced in a casting process that is also used to manufacture stock lenses. 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.
III. Round top bifocal lens:
 | This lens is also called a CFR (Croma Free Round - In reference to the glass fused lenses), and a kryptok lens. This lens has been offered in widths ranges including 22, 25 and 28mm, however some sizes and mediums in this lens have been phased out and are no longer available. This lens gives the user a narrower initial reading range up top, because of its round top. |
Bifocal lens can be called a multi purpose lens. It has 2 different fields of vision in one visible lens. The larger of the lens usually has the prescription necessary for you to see for distance. However, this can also be your prescription for computer use or intermediate range, as you would normally be looking straight when you view through this particular part of the lens. The lower part, also called the window, typically has your reading prescription. Since you generally look down to read, this is the logical place to put this range of vision assistance.
| A simple way of wearing bifocals, is to put them on and focus for distance through the upper segment, then, without moving the head (this is most important—no head movement) to lower the eyes to read a book held 18" away and down at an angle of 30 degrees. One thus uses the lower segment for reading. This exercise must be repeated over and over again so that the brain and the eye adapt to a new system of reading. . |  |
IV. The process of uncoated lens:
V. Packing&Shipping:
| Envelop | Choice 1 | Choice 2 |
| White envelop | color envelop with customer design weight: 157g size: 9*9*9cm |
| Outer box | standard export paper carton 38cm*48cm*35cm(0.064 CBMS) |
| about 500 pairs of finished lenses per carton, 21kgs | about 100 pairs of semi-finished lensesper carton, 15kgs |
| Lead time | Depend on the quantity |
| Carrier | We can choose for you or offer us your cooperative company |
| Payment terms | 30% T/T in advance, the balance before shippment |
VI. Our service:
1. Our Customer service will begin to track the product processing every day until you receive the goods and verify the product quality when you finish the payment.
2. Online via SKYPE,Whatsapp;Also through mail, voice phone, message could contact us at any time!
3. Follow up the case, record the entire process. Solution will be provide with 24 hours.
Meanwhile,the problem complaint will be reported to QC department.
QC will find defect from which department ,who is in charge to identify responsibility.
4. Collect and record all the voice from each customer respond , suggestion, requirement.
5. We own the best after-sale service,if any problems happen,our team will do our best to solve for customers.
Product Tags:
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SF CR39 1.499 Round Top Bifocal Lens Blanks 70mm Diameter 58 Abbe Value Images
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