High index lens

When purchasing high index lenses (1.61, 1.67, 1.74), you must prioritize the Abbe Value, which determines optical clarity; a higher value means less chromatic aberration. Ensure the lenses feature Multi-Layer AR (Anti-Reflective) Coating, as high index materials reflect more light than standard plastic. Additionally, verify the Tensile Strength, especially if you are sourcing for rimless or groove frames, to prevent cracking during glazing.

For the US market, lenses must meet FDA 21 CFR 801.410 (Drop Ball Test) for impact resistance. For the EU, CE Marking and compliance with ISO 12870 or ISO 14889 are essential. If you are sourcing from Made-in-China.com, look for suppliers with ISO 9001 certification to ensure consistent monomer quality and coating durability.

There is a significant price jump between 1.67 and 1.74 index lenses due to the raw material costs of the chemical monomers (like Mitsui Chemicals' MR series). For mass-market retail, 1.61 index lenses offer the best balance of thinness and cost-efficiency. Reserve 1.74 index lenses for premium lines targeting prescriptions above -6.00 SPH, as the marginal utility for lower prescriptions does not justify the higher wholesale price.

Beyond standard HC (Hard Coat), you should specify Super Hydrophobic (Easy-Clean) coatings to reduce smudging. With the rise in digital device usage, Blue Light Blocking (Blue Cut) technology—either via mass-tint or coating—is now a standard requirement for most professional buyers to increase marketability.

Request a pre-shipment sample and view it against a pure white background to check for yellowness index. High index materials can oxidize if stored improperly. Use Made-in-China.com's Inspection Service to verify that the batch matches the approved golden sample in terms of base curve and clarity before final payment.

Negotiate based on volume tiers and packaging. Suppliers often provide a lower unit price if you accept white-label (neutral) envelopes instead of custom branded packaging. For long-term contracts, ask for a price lock agreement on MR-series monomers to protect against fluctuations in chemical raw material costs.

Lenses are sensitive to pressure and temperature. Ensure the supplier uses vacuum-sealed inner packaging and double-walled corrugated export cartons. For air freight, specify that pallets should be shrink-wrapped to prevent moisture ingress, which can degrade the hydrophobic top coat during transit.

Always utilize Secured Trading Services provided by Made-in-China.com to ensure your payment is only released after the shipping documents are verified. Avoid direct wire transfers to private accounts; ensure the beneficiary name matches the company name on the business license and the platform profile.