The two most popular functions of a lens coating include anti-reflection and protection from harmful light(1). The question is, how do these seemingly magical and invisible layers on your lenses make such a difference?
In our latest blog, we’ll look at how lens coatings work and what makes them such an impressive technological advancement for your lenses.
Anti-reflection coatings are used for many different products such as camera lenses, solar panels and of course glasses lenses. The technology has been around for nearly a century, has been applied to optical lenses for nearly three decades and has been adapted and improved to changes in the environment, your needs and findings from research.
In simplest forms, a lens coating contains many nanolayers stacked to work together in partnership to improve what your lenses look like, your clarity of sight as well as promoting good eye health and giving your lenses extra protection. These layers are so small that they do not affect the thickness or weight of your lenses and cannot be seen, yet they do so much for your eyesight and lenses.
Let’s explore the different layers and benefits.
Lens coatings for clearer sight
Our Crizal Sapphire UV lens coating is the first of its kind that takes your needs into account. It is equipped with a patented nano layer that is able to tackle light from every angle, in order to reduce bothersome reflections.
The recalculated layers are applied to both the front and back surfaces of your lenses, minimising reflections caused by sunlight and artificial light sources such as household lights, phone screens, camera flashes, etc.
When reflections and glare affect are lenses research has shown that we end up adopting a change in posture which can lead to physical discomfort or if the glare is really distracting we even remove our glasses which contradicts exactly what are glasses are trying to achieve.
Having an anti-reflective lens coating can be hugely beneficial for your visual and postural comfort. By reducing the amount of reflections your vision will be purer with more vivid images. Those distracting reflections will also be eliminated from the front of your lenses making them appear transparent to others. Your family and friends won’t even notice you’re wearing lenses and will be able to see your eyes clearly improving your aesthetics(2).
What’s more, Crizal Sapphire UV provides your lenses with E-SPF 35; the highest level of UV protection in a clear lens design(3). UV is one factor that drives the development of cataracts(4). This level of Eye-Sun protection factor is achieved through years of research and development of specific layers used within the coating.
Lens coatings that protect your vision
Another of our popular lens coating, Crizal Prevencia, can further protect your eye health from harmful light; including blue-violet light and UV light. While most of the visible light spectrum is essential for seeing colours, shapes, details and for our overall wellbeing, Blue-Violet and UV light can both contribute to premature eye ageing(4)(5).
Light Scan technology in Crizal Prevencia lens coatings will selectively filter out Blue-Violet light, while blocking 100% of UV light. Furthermore, the lens coating will also protect wearers from UV light that may hit the back of the lens by preventing it from reflecting off of the back of the lens into the eye.
By eliminating back surface reflections as well as the front, Crizal lens coatings offer a great solution to getting more out of your lenses.
Protecting your lenses
As well as protecting your vision and enabling clearer vision, lens coatings are also designed to help improve lens durability. Features like scratch-resistance and smudge-repellence are key properties of a lens coating.
Scratch-resistance lens coatings work by a nano millimetre layer be applied to your lenses, often behind the anti-reflection layer. This is designed to gradually increase hardness, in order to protect your lenses from scratches.
Smudges appear usually because of uneven nano molecules on the surface of lens coatings. Lens coatings created with fluorinated molecules in a consistent pattern, like Crizal, offer a much more superior smudge-repellent layer. Your lenses are touched more than you think throughout the day, by making them smudge-repellent your glasses will be clearer for longer and will be much easier to clean. Clean and clear lenses result in better eyesight.
An oleophobic layer is added to make your lenses repellent to dirt. Dirt from your daily environment, even dead skin or hairs can stick to your lenses. With an oleophobic layer added your lenses become dirt repellent making it easier for your to clean your lenses for better vision.
Many lens coatings can offer a water-repellent feature which can come in handy, especially with our weather! This works by filling microscopic gaps in the coating with hydrophobic molecules, which create the water-repellent effect. This can smooth the surface of the lens, so that any water droplets will roll off the lens surface without leaving a trace.
Finally, dust-repellent properties can ensure your lenses remain clear and clean. An anti-static layer is applied to the lens coating, which prevents any dust particles from sitting on the lens to make them look clean to others while providing clarity for you so that you see all the details of whatever you’re looking at clearly.
(1) Harmful light = UV and Blue-Violet light(2) Perceived invisibility based on Wearers Test 2017. (Fr) N = 50 - resulting from a better perception of anti-reflective feature.(3) The E-SPF® index depends on the lens material itself and the coating. E-SPF® is a global index rating the overall UV protection of a lens. E-SPF® was developed by Essilor International and endorsed by 3rd party experts. Lens performance only. The E-SPF® index excludes direct eye exposure that depends on external factors (wearer’s morphology, frame shape, position of wear). E-SPF®=10 for Crizal® UV lenses with Essilor Orma 1.5®.(4) McCarty CA, Taylor HR. A review of the epidemiologic evidence linking ultraviolet radiation and cataracts. Dev Ophthalmol. 2002; 35:21-31. Eye health relies on various factors (age, genetic, smoking, diet …). Light is one of the modifiable risk factors on which an ophthalmic lens may act. (5) Sunlight and the 10-year incidence of age-related maculopathy: The Beaver Dam Eye Study. Arch. Ophthalmol., 122, 750-757. New discoveries and therapies in retinal phototoxicity, Serge Picaud et Emilie Arnault, Points de Vue N°68, Spring 2013.