LENS TYPES & TECHNOLOGY

HELPFUL INFORMATION FOR SELECTING LENS TYPES AND TECHNOLOGY

Edge Optics would like to help you understand what is involved in the purchase of modern eyewear. Learn more about lens types, technology definitions, and Sport-Specific Guidelines that will guide you through the process of finding your perfect eyewear!

Polycarbonate lenses

Polycarbonate Lens Types

Impact-resistant blended lens material. Polycarbonate is lighter and thinner than standard plastic and glass lenses, it is impact-resistant and won’t shatter, however, it can create less than optimal color visualization compared to glass and plastic, although most people do not notice this difference. This lens is recommended for kids’ glasses, sport glasses, and occupational hazard glasses.

Polarized lenses

Polarized

Polarized lenses are oriented to block the horizontally vibrating component of light, which reduces reflected light. This helps decrease driving fatigue from road reflections and allows visualization of objects under the water surface (great for fishermen), comfort at the beach, or a more enjoyable day on the ski slopes by reducing glare caused by reflections from the snow. The Edge Optics experts can show you some tricks in determining if a lens is polarized or not! One thing you may notice is that you will see a rainbow effect on the windows of your car when driving because of the way polarized lenses transmit light. You will get used to it!

CR39-Plastic Lenses

CR39 Plastic Lenses

This is the industry-standard everyday lens. It is lighter than glass lenses and not as likely to shatter or chip but still provides a similar visual performance. CR-39 transmits 92% of visible light (8% is lost through surface reflections) and has inherent UV inhibitors that block UV light below 350nm.

Photo-Chromic lenses

Photochromic Lenses

A Photo-chromic lens lightens its tint when there are lower light levels and darkens the tint when the light intensity increases. Traditionally, these lenses are activated by UV light which is great for transitioning from indoors to outdoors. Because of UV blocking properties, present in today’s auto windshields, these lenses did not darken enough when driving. This was a complaint often heard from the consumer. However, new photochromic lenses are available that are polarized AND darken according to visible light waves which allows them to change behind the auto windshield. This is the wave of the future—get it (light waves…)?!

Trivex/NXT Lenses

Trivex/NXT

A new lens that is more impact-resistant and lightweight than polycarbonate lenses! They are usually an aspheric design which provides better optics with less distortion. The lenses are thinner than plastic or glass lenses. The Trivex/NXT is recommended for kids, sports frames, and occupational hazards. Trivex/NXT provides good quality and durability.

Blue Light Filtering lenses

Blue Light Filtering

LDC and LED screens for digital devices emit most of the light in the blue light wave range.  This is significant because these wavelengths are right next to Ultraviolet on the EM spectrum. These wavelengths are more intense in our visual system.  In the lab, we know these wavelengths can cause physical damage to our tissues.  These wavelengths of light scatter more easily, making them harder to focus on creating strain.  By using blue light filtering lenses, we can reduce the intensity of our screens, reduce fatigue, and eye strain, and potentially prevent damage to our eyes

Tinted Lenses

Tinted Lens Types

Brown and Grey tints are the most chromatic neutral tints, meaning they will not distort the actual color of objects. Brown lenses like yellow tints have a higher absorption of shorter visible wavelengths(blue light), which is responsible for most light scatter, thereby increasing contrast sensitivity on a hazy, smoggy, snowy, or overcast day.

UV Light/Protection

Ultraviolet light is a part of the light spectrum received by the sun.

Ultraviolet light is divided into 3 categories based on their wavelength:

  • UVA is between 400=320nm
  • UVB 320-290nm
  • UVC 290-200nm

UVC is filtered by the earth’s atmosphere; however, mountaineers should still be concerned about possible exposure because UV light increases in intensity at high altitudes. This could also apply to really any active Colorado resident.

Sand reflects 20-30% of UV light, and snow reflects 85-95% of UV light, compared to grass and water at least 10%. This is why it’s crucial to wear UVA/UVB-protected eyewear even in the winter! You can literally sunburn your eyes. This is very painful and NOT recommended! UV light is a major cause of cataracts and macular degeneration in the eye, as well as cancers and other skin diseases in and around the eye. People who live in an area where the average amount of sunlight exposure is 12 hours have four times the amount of cataract formation compared to those who have 7 hours of exposure. Don’t forget this also applies to your KIDS!!! They have even more sensitive eyes and need that protection. It is so sad to see parents with sunglasses pushing their child in a stroller that is just blinded by the sun. Think about it! This should be identified as a real health hazard. YOU need to be on the cutting edge!

A/R or non-glare coatings

These coatings help reduce glare from surface reflections on your lenses. A coating placed on the front side of your lenses reduces the glare appearance of your lenses to other people as well. You will want this technology so that people can see your eyes. A/R coating also increases the light transmission to your eyes for low light conditions (at night) so you will see more than someone who does not have A/R coating on their lenses. An A/R coating on the back surface of your lenses cuts reflections you see in your lenses from light sources behind and to the side of you.