Lens Coatings

Spectacle lens technology has developed significantly over the past 10 years with many options available to enhance vision, maintain eye health and make eyewear more resilient.

Among those options are the many coatings that can be applied to lenses, including anti-reflective, scratch-resistant, anti-fog, mirror coatings, and UV treatments.

These options are often not well understood by patients and they need to be carefully explained to promote acceptance and avoid confusion.

Not All Coatings Are Equal

It is important to note that not all coatings are the same. They vary in the degree of protection, the number of layers, how well they adhere to the lens surface and how they cope with temperature changes and different chemical cleaning agents.

These options are often not well understood by patients and they need to be carefully explained to promote acceptance and avoid confusion

Scratch Resistant Coatings

Scratch resistant coatings are applied to give lenses a harder surface. These coatings vary in the degree of hardness and therefore the extent to which they prolong the life of eyewear and maintain clearer vision.

Anti-Reflective Coatings

An antiglare or anti-reflective coating can simply be explained as a layer applied on lenses to increase the clarity of vision and protect the eyes against fatigue. The coating does this by eliminating disturbing lights and shadows.

Current technology in anti-reflective coatings can virtually eliminate the reflection of light from eyeglass lenses, allowing 99.5 per cent of available light to pass through the lens and enter the eye for good vision. This helps considerably when driving at night, and can reduce glare from computer screens. Additionally, anti-reflective coatings are more cosmetically appealing because the wearer’s eyes are clearly visible.

Once again not all anti-reflective coatings are the same. They vary in terms of light transmission, hardness of the scratch resistance and the number of layers which are deposited in the coating process.

These additional layers can greatly assist by making eyewear easier to clean and maintain, consequently impacting quality of vision.

Other Layers

Anti-static and Hydrophobic Coatings
These coatings behave like a force field around the lens to repel dust, making them useful in harsh environments, particularly when dust is common.

Additionally, the hardened, anti-static top-layer can also have oleophobic properties, which makes the lens water repellent so that it is easier to clean when smudges or fingerprints are introduced to the surface.

UV
Most people are aware that UV exposure can lead to skin cancers and skin damage, however the effect of UV exposure and its cumulative effects on the eyes is easily forgotten.

It is a duty of care, and part of our role as optometrists, to continually educate all patients and reinforce the message that UV can be harmful to the cornea, retina and conjunctiva. Since the effects are cumulative, protecting kids’ eyes is important and this should form part of every paediatric examination.

UV coatings applied to spectacle lenses can block 100 per cent of harmful UVA and UVB rays to ensure much better eye protection. Additionally, since up to 50 per cent of UV radiation penetrating the eyes is reflected off the back surface of prescription eyewear, it is important to coat the back surface of the lens as well.

Blue UV
Digital devices and LED light sources provide significant benefits to our daily lives, however they contain a high proportion of blue light. With increasing use of these devices your patients are being exposed to more blue light than ever before. This may have detrimental effects to their eye health and certainly disrupts circadian rhythms. Discussion about the effect of blue UV should now be a routine part of your patient education in the exam room. The recommendation of these coatings is set to become a standard of care.

Anti-fog
Lens fogging is caused by tiny water droplets that form by condensation on the lens surface when lenses are significantly cooler than the surrounding air temperature.

By adding an anti-fog coating, lenses, and therefore vision, remains clear when the transition is made from a cold environment to a warm one. An anti-fog coating may also keep your patients’ lenses from fogging up during sports and at other times when they are hot and perspiring.

The Opportunity

Recent developments in coating technology mean we can now provide real benefits to patients by ensuring their vision is clearer, assisting in the prevention of eye disease, and offering eyewear that lasts longer and is easier to maintain.

It is vital that we educate our patients on UV control and recommend coatings which will help maintain their eye health and deliver clearer vision.

Jim Papas is an optometrist with extensive experience in contact lenses. A practice partner of eyeclarity, he is an expert in retail, business strategy and brand development. Jim has won multiple awards for customer service and commercial innovation, including the 2015 Australian Retail Innovator of the Year award. His Melton eyeclarity practice won The Melton Business Excellence Award for the best Retail Business for 2016.