Mitsui Chemicals’ MR™ High Refractive Index Ophthalmic Lens Monomers Picked up by Costco as Standard Option for Glasses

Major US retailer makes full changeover to MR™ series as of March 2021


Mitsui Chemicals, Inc.

Mitsui Chemicals, Inc. (Tokyo: 4183; President & CEO: HASHIMOTO Osamu) today announced that its MR™ series of high refractive index lens monomers has been picked up and launched as the standard option in glasses sold by major U.S. retailer Costco Wholesale Corp. (Washington; CEO: W. Craig Jelinek).

In previous years, Costco has mainly offered polycarbonate ophthalmic lenses, which are the standard in the U.S. market. But after having started to move over to lenses based on Mitsui Chemicals’ MR™ series last October, the company is now completing a full switch in March 2021.


Costco holds the optical performance of the MR™ series in high regard, seeing the MR™ series’ concept of lighter, thinner products with more refined performance as an ideal fit with its own goal of providing customers with high-performance products from excellent brands.

Spurred on by having its material adopted as the Costco standard, the Mitsui Chemicals Group will pursue further transition from polycarbonate to lenses based on Mitsui Chemicals’ MR™ series, and further sales growth, as it looks to improve people’s Quality of View (QoV)* in the U.S. market.

*Quality of View (QoV):
a measure of quality and satisfaction in all areas related to eyes and eyesight in our lives. The term encompasses vision optimization and comfort, ocular health, and measures to prevent optical diseases.

High refractive index MR™ ophthalmic lens monomers

Making use of an unparalleled material known as thiourethane resin, the MR™ series exhibits characteristics not found in conventional resins. The series is rated highly as a lens brand of its own that underpins the superb quality of the world’s top brand lenses, and is used in many ophthalmic lenses throughout the world.


  1. Thin and light:
    Even high-power lenses can be made thin and comfortable to wear.
  2. Safe and resistant to breakage:
    The toughness of thiourethane resin improves impact resistance even for thin lenses, and the material can be formed into virtually any design.
  3. Lasting appeal:
    Thiourethane lenses feature high weather resistance and resist discoloring over time.
  4. Clear views:
    Due to the prism effect, which disperses light passing through a lens, color fringing (chromatic aberration) typically becomes more evident in the view as the optical power of a lens increases. Lens materials with high Abbe numbers,* such as the MR™ series, can minimize chromatic aberration.

*The Abbe number is an index associated with chromatic aberration.