The Importance of Backside UV Protection

Our sun provides us light, energy, and heat. It is nearly one million miles in diameter, almost 100x times larger than the earth, and is about 93 million miles away from the earth, causing its light to take about 8 minutes to reach the earth’s surface. It is also the most powerful source of ultraviolet (UV) rays to life on earth.

UV rays are found on the visible light spectrum ranging from 100 – 400 nanometers (nm). We categorize UV into three separate groups: UVA, UVB, and UVC. Fortunately, we do not have to worry about UVC as all of these rays are absorbed by the ozone layer and atmosphere, never making it to earth's surface. 

However, some of the UVB rays and all the UVA rays will penetrate the atmosphere and make it to earth. These are the rays we focus on protecting. UV is known to have damaging effects to not only our skin but our eyes as well. Overexposure to UV can lead to cataracts (cloudiness of the crystalline lens), macular degeneration (permanent vision loss), photokeratitis (temporary vision loss), pterygiums (growths on the eye) or even skin cancer.

Many of our lens materials have UV protection built into them. Standard plastic (CR-39) and glass lenses are the only lenses that do not have full UV protection built into the monomer of the lens. Many of our lens treatments also have UV protection, like our Sensity™ Family of photochromic lenses and our Coppertone™ polarized lenses.

How much protection is needed? 

Standard UV protection works by reflecting the UV back into the world. This protection prevents the UV rays from penetrating the lenses and entering the eye. When we apply an anti-reflective (AR) treatment to a lens, the light waves reflected from the coating surface will cancel out the light reflected from the front lens surface. 

Similarly, when we apply Recharge™ to a lens, we reflect the blue light back into the world, creating a slight blue reflection on the lens. Our Recharge lens treatment reduces harmful blue light by 10 percent compared to conventional anti-reflective(AR) treated lenses and by up to 30 percent through a combination of absorption by the lens material and reflection. The treatment optimizes transparency and has the same scratch resistance properties that our ECPs have come to expect from Hoya treatments. Recharge offers an overall treatment that repels scratches, glare, water, dirt, and protection against harmful blue light.

So why do we need backside UV protection?

Unfortunately, lenses with AR treatment will also reflect UV rays off the back of the lens when sunlight shines from behind. While many spectacle lenses offer inherent 100% UV protection from light incidents to the front surface, we should be concerned with the reflection of UV incidents to the back of those spectacle lenses. According to a study conducted by Pacific University, 10% - 50% of UV incident to the back surface of an anti-reflective treated spectacle lens (without backside UV protection) is reflected onto the eye and surrounding skin. 

HOYA Super Hi-Vision EX3+® Provides UV Protection

HOYA’s Super Hi-Vision EX3+® treatment has a unique backside that offers total UV protection. Since anti-reflective treated spectacle lenses reflect 20% of the light incident to the back surface, a decrease in UV exposure of approximately 20% can be realized.

Instead of reflecting the UV back into the world, the lens treatment disperses the UV throughout the lens. Lenses treated with Super Hi-Vision EX3+® eliminates the backside UV reflection that occurs in other lenses. This treatment gives you complete UV eye protection regardless of the sun's location. 

Added benefits of HOYA Super Hi-Vision EX3+®

Scratch Resistance 

Super Hi-Vision EX3+® uses a hard coat thermal curing process that improves the scratch resistance above that of other Hoya HiVision AR treatments. This extra step places the lenses in a thermal unit for curing. The thermal process enhances the hardness of the foundation for the AR stack.

Clear Vision 

Experience sharper, more comfortable vision with AR treatment that eliminates glare and reduces eye fatigue while improving the cosmetic appearance and enabling safer nighttime driving.

Clean Vision 

EX3+™ AR treatment offers the benefits of being easier to clean and staying cleaner longer by using hydrophobic and oleophobic properties that are specifically engineered to work with the other layers of the AR stack.

• Hydrophobic properties allow the lens surface to repel water.
• Oleophobic properties force oil that contacts the spectacle lens to stay on the surface and not permeate into the AR stack. 

Super HiVision EX3+® is the best solution to overcome your patients' hesitation toward Anti-Reflective lens Treatment.

HOYA’s in-house produced lens materials and jointly manufactured lenses meet the highest quality standards, all while reducing the most significant annoyances. This treatment is the perfect solution for anyone interested in protecting their investment and keeping their lenses in excellent condition all year round.

Thanks to a special composition of various layers, Super HiVision EX3+® treatment keeps lenses safe and glasses wearers happy, even after years of usage.