What is the Highest Index Lens Available in the U.S.?

If you’re reading this you’re probably familiar with the characteristics of high index lenses.

Highest Index Lens Available in the U.S.

What is the Highest Index Lens Available in the U.S.?You know that vision-correction prescriptions that fall within the stronger prescription range can benefit from the reduction in thickness and possible reduction in weight that high index lenses allow. You also know the trade-off is that high index lenses are more expensive, more fragile than most standard-material lenses, and feature more chromic aberration (designated by the Abbe value scale), which can be distracting to wearers sensitive to such anomalies.

You may also know that as lens index increases, both weight and reflected light values increase. For instance, a 1.74 high index plastic lens has a specific gravity of 1.47 and a reflected light rating of 14.36, while a 1.80 high index glass lens bumps those numbers up to a specific gravity of 4.02 and a reflected light rating of 18.85. Still, for those who require extremely strong prescriptions, high index lenses at the upper end of the spectrum can certainly be worthwhile alternatives to the thick, “Coke Bottle” lenses that lower-index materials produce.

So how high does the high index scale go? 1.9 is currently the highest available material worldwide, but it is not approved for sale in the United States by the FDA (Food and Drug Administration). 1.8 high index lens material is the highest level that is FDA-approved for U.S. sale and distribution.

The reason for this is the more stringent impact-resistant standards set by the FDA. In accordance with FDA regulation 21 CFR 801.410(d)(1), a “Referee” or “Drop Ball” test – interchangeable terms for the approved impact test – must be performed on all lens material types. The regulation states, “In the impact test, a 5/8-inch steel ball weighing approximately 0.56 ounce is dropped from a height of 50 inches upon the horizontal upper surface of the lens. The ball shall strike within a 5/8 inch diameter circle located at the geometric center of the lens. The ball may be guided but not restricted in its fall by being dropped through a tube extending to within approximately 4 inches of the lens. To pass the test, the lens must not fracture….”

Shop High Index Glasses1.9 high index lenses are fragile and brittle enough to fail the test described above, hence they are not FDA-approved.

Guide to High Index Lenses 8 Responses to What is the Highest Index Lens Available in the U.S.?
  1. Sarah Meriggi
    June 1, 2014 | 5:00 am

    Hello:

    Where can I find a physician who will make high index 1.9 thin lenses? I am willing to travel to Canada. Just need the name of someone who can do it while I wait a few days in Canada. I did have very thin lenses in my glasses, but two years later, efforts to obtain new lenses have resulted in a heavier weight and thicker lense. This is due to United States law.

    Thank you.

    Sarah

    • Kieran Hunt
      June 5, 2014 | 1:56 pm

      Hi Sarah,

      We do not have a relationship with any opticians’ offices. If you’re interested in getting prescription glasses with high index lenses, I recommend visiting our sister site, http://www.myeyewear2go.com, and taking a look at the selection there.

      Best,
      Kieran Hunt
      HighIndexLenses.com

  2. Christine Jacobson
    June 13, 2014 | 12:47 am

    I am interested in the 1.9 high index glasses. My prescription in contact lenses is on the right eye -16 and in the left -23. I’d like to purchase a pair of your glasses as a back- up for my lenses. I need to wear me contact lenses 24/7 and my eye are very sensitive in the evening. If i would be able to order the high index glasses i could wear them at home to give my eyes a rest. I am a 62 year old women and wear contact lenses for 45 years. I don’t know how long am able to wear them?
    Please let me know what i need to do to order them from you. Do you sell the 1.9 index glasses? I know they aren’t approved here in USA. If so, can you let me know where I can purchase them? With my prescription i only want the 1.9. I have 2 other pair of glasses with very thick lenses and i can’t wear them outside of the house.

    I’d appreciate your help and response.

    Christine Jacobson

  3. Hi Kieran
    December 7, 2015 | 10:09 pm

    i m having the same probleme as Christine Jackobson, i m 51 years old, shopping for the 1.90 high index lenses, can you please help to how to procceed
    202361007
    youssef

  4. Leon Gersh
    July 24, 2016 | 12:55 am

    What is the difference between 1.74 index and 1.90
    How much lighter and thinner is the lens ?
    Is high index 1.90 lenses available in US ?
    I need to fill my prescription now .
    I look forward to your response .
    Thank you .Leon

    • Ryan Phillips
      July 25, 2016 | 7:19 pm

      The difference is very small between the 1.74 and 1.90 lenses. They are now available for purchase, as this article is 2+ years old.

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