Sponsored by Shamir Insight Inc.
By Linda Conlin
By now, the dangers of ultraviolet (UV) radiation are known to eyecare professionals and the great majority of consumers who want 100 percent UV protection. But even with lenses that claim to block 100 percent UV, are they getting 100 percent 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.
Fig. 1 The lens on the left is Shamir Galcier PLUS UV and the lens on the right is an example of Newton Rings on a lens. Note: Both lenses have been analyzed on the same surface utilizing the same analyzation method.
It Starts with a Premium AR Coat
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-resistant properties along with increased durability. 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.
Repel: With oleophobic and hydrophobic properties to enhance 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 percent 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 percent UV protection in lenses doesn’t mean 100 percent UV reaching the eye, making backside UV vital for eye health and safety.
Glacier PLUS UV is available on all Shamir Freeform lenses in Polycarbonate, Hard Resin, Trivex and 1.67 and 1.60 indices. Lenses are available clear, in 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 eyecare provider, ensure that they receive lenses that produce the highest acuity and UV protection while being easy to clean and durable.
For patients who already use AR coatings, Shamir Glacier PLUS UV can be recommended to improve the patient’s visual 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.