Linda Conlin, Pro to Pro Managing Editor

By now, the dangers of Ultraviolet (UV) radiation are known to eye care professionals and the great majority of consumers who want 100% UV protection. But even with lenses that claim to block 100% UV, are they getting 100% protection?

UV attenuating lenses block UV from entering through the front of the lens, but those harmful rays reach the eyes from all angles and are even reflected into the eye from the backside of the lens causing UV exposure that UV-protective materials and treatments that obstruct transmission through the front of the lens, can’t prevent. A 2018 study in Germany found that combining a UV attenuating lens with anti-reflective (AR) coating that also reduced UV back reflections provided the most efficient all-day UV protection. 

It starts with a Premium AR Coat

Figure 1
To combine UV protection (front and back) with glare free lenses, Shamir’s premium quality AR coating utilizes advanced technologies to provide a cutting-edge, glare-reducing solution for your patients. The basic concept for how anti-reflective coatings work is the optical interference model. Each coating layer in the AR stack combines with previous layers to cancel out a broad range of light waves by introducing destructive interference. Thus, reflective properties of that range of light are neutralized. By applying the principle of optical interference, we can increase light transmission through a lens to nearly 99 percent in most of the spectral range. The result is a reduction of reflections over a broad range of wavelengths and clear, crisp vision for your patients.

Reduce:  Even on an AR coating, residual reflections can be distractingly prominent. Shamir’s innovative Low Reflection Finish provides dramatically reduced cosmetic reflections off the lens and reduces visual glare for the wearer, providing a crisp, clear visual experience.  Shamir has also addressed a cosmetic issue found on many AR coatings – the “rainbow” effect. To reduce this effect, Glacier PLUS UV employs Newton Ring Reduction technology (Fig 1) that ensures that the hard coat and AR and lens material are index matched. 

Resist:  Shamir Glacier PLUS UV features improved anti-static and scratch resistance properties with a durable surface. By understanding and defining the components for a cohesive bond, Glacier PLUS UV has greater adhesion to all substrates. (Fig 2) The coating helps lenses resist smears, smudges, dirt, and dust, so they stay clean and enhance visual acuity.  

Figure 2

Repel:  Developed with oleophobic and hydrophobic properties to enhance your visual acuity, this coating helps to repel dirt, dust, and water, requiring less cleaning and resulting in a longer lasting coating.

Back surface UV: In a paper published in 2008, K. Citek, OD found that back surface AR reflects up to 40% UV. That means the wearer has no UV protection between the back of the lens and the eye, including the delicate extraocular tissues: eyelids and surrounding skin of the eyes.  A 2012 study showed that the UV reflection risk is highest when the wearer is facing about 145 degrees from the sun, which means that the sunlight is coming from behind the wearer, just over his or her shoulder. Consider that the wearer would be facing away from the sun, and possibly not aware of any risk at all!  It’s concerning that the standard definition of 100% UV protection in lenses doesn’t mean 100% UV reaching the eye, making backside UV vital for eye health and safety.

The benefits to patients are: 

  1. Improved scratch resistance

  2. Ease of cleaning

  3. Enhanced anti-static properties to repel dust and dirt

  4. Front and Backside UV protection

  5. Less visual distraction with:

    1. Reduced birefringence

    2. More comfortable vision with reduced visual glare, especially for night driving

  6. Better appearance without distracting and cosmetically unattractive reflections off the front lens surface referred to as ‘cosmetic glare’

Glacier PLUS UV is available on all Shamir Freeform lenses in Polycarbonate, Hard Resin, Trivex, and 1.67 and 1.60 indices. Lenses come in clear, Transitions, XTRActive, polarized and Blue Zero to suit every patient’s needs.

The Bottom Line

At a time when patients expect more from their lenses, Shamir Glacier PLUS UV provides a complete package of clarity and comprehensive UV protection in a state-of-the-art lens. As their trusted eye care provider, ensure that they receive lenses that produce the highest acuity and UV protection while being easy clean and durable.

For patients who already use AR coatings, Shamir Glacier PLUS UV can be recommended for a better patient experience.  For patients who don’t yet wear AR, it may provide another incentive to choose the enhanced clarity and protection that only premium AR with comprehensive front and back UV protection can offer.