Demystifying Glasses Coatings

For many patients, when I am performing their refraction they tell me it is a very stressful experience.  I try to make things easier by showing patients choices slowly and several times, and reassuring them when they select the same answers.  The refraction process can be stressful, but your doctor is making sure on the other side of that machine that you are getting glasses that you will be able to see clearly through.  You aren't going to end up with super thick glasses that you can't see through, no matter how many "wrong" answers you give. After all that, you finally get your prescription, and now you have the arduous task of selecting and purchasing glasses.

First; you have to select frames.  Styles, shapes, colors; that's a lot of choices!  Sometimes my patients come back several days in a row with friends and family and significant others, just to make sure they are picking the right frame.  The frames have to be comfortable and able to perform with your prescription, and of course, you have to feel like you look great in them.

But wait, you still aren't finished!  When you finally select your frames, your optician is going to review your prescription and start offering even more choices.  Thinner lenses?  Anti-reflective coating?  Scratch coating?  Transitions?  Even for people who are normally quickly decisive, the process can be overloading.  Let's clear one thing up though:  it doesn't have to be.  Here's a quick breakdown for what you need for your glasses to perform to their fullest:

1) Lens Material
Glasses are made out of several different materials, and depending on your prescription or medical conditions, your doctor is going to have a strong opinion on what will perform best.
-CR 39:  Great option for lower prescriptions; your "standard" material

-Polycarbonate:  a MUST for children or people with one eye due to previous injury or amblyopia.  Polycarbonate or a material called Trivex are required for safety glasses and preventing shattering

-High Index:  For higher prescriptions (over 4.00D typically) to keep lenses from being so heavy and thick

Photo via

-Glass: Yes, they still make this.  But select at your own risk; most doctors require you to sign a waiver if you insist on glass due to the major safety and shatter risks

2) Coatings
All glasses from a reputable optical should come with some UV coating and a baseline scratch coating with a warranty (typically 1 year).  I consider UV and some scratch warranty a minimum. Glasses are expensive, and they scratch very easily--completely decimating your vision when a scratch occurs.

Without AR coating on the left you can see major glare photo via

-Anti-Refective coatings:  Do you wear your glasses at the computer?  Do you drive in your glasses in the rain or at night?  If you answer yes to any of these, you need anti-reflective coating to prevent glare  from disrupting your vision while wearing glasses.  If you need high index lenses, then anti-reflective coating isn't even optional.  Your glasses simply won't perform without it.

-Scratch Coatings: More expensive scratch coatings are essential when you have more expensive anti-reflective coatings.  Anti-reflective coatings improve glare, but make your glasses more at risk for scratching.  Protect your investment with a better scratch guard to make your glasses perform longer.

-Transitions or photogrey:  If you spend a lot of time in and out of doors having UV protection can prevent sun damage in and around the eyes as well as reduce light sensitivity.   And they are 100% UV blocking which means they function as well as full sunglasses at protecting ocular health.