Which lens coatings do you need?

Authored by Shivkumar Janardhan, CEO, Essilor India

India 23 December 2016: If you think spectacles can only offer better vision to you, you probably have missed out on the enormous leap the lens technology has undertaken in recent years!
While correcting your refractive Error remains their primary role, spectacles today are much more than just vision correction devices. Backed by extensive research and supported by a greater understanding of visual health, new age lenses also provide active protection to the eyes against environmental and man-made threats such as UV radiation and LED lighting. Lens technology has also progressed to meet the needs of the ‘new’ threats of the digital age such as increased eye fatigue and digital strain.

If you are struggling with digital overload because of spending too much time on the computer, your spectacle lens can incorporate ‘anti-fatigue’ technology; if you are a night owl who loves to drive around highways when the world sleeps, the ‘anti reflective’ lens technology can allow you a glare free and safer vision.

Lens coatings are surface technologies that help optimize and protect your vision. Different lens coatings play different roles, and their benefits include UV protection, Fatigue reduction and Glare Protection, among others.

Most people in India still buy spectacle lenses with a single minded agenda – that of meeting their prescription needs. However, there is an increasing number of more discerning buyers who want to make the most of their spectacles. For such people, there is a range of lens coatings they can choose from:

Ultraviolet Treatment: UV coating on your lenses is to the eyes what sunscreen lotions are to the skin. While we all know that exposure to UV radiation can have harmful effects on the skin, most of us are blissfully unaware that UV radiation is also a serious health hazard for our eyes. Not only is prolonged exposure to UV radiation associated with increased risk of skin cancer, it is also believed to cause cataracts, retinal damage, macular degeneration and eye cancer.

UV coating is therefore one lens technology that most of us need. In fact, Essilor has developed a rating system called E-SPF (Eye-Sun Protection Factor) to certify the UV protection index of a lens. The higher the E-SPF, the better is the UV protection capability of the lens. People who regularly spend time outdoors should most certainly opt for UV protection on their lenses. A lot of people use sunglasses which offer UV protection for the eyes. However, for people who need prescription power in their eye-wear daily spectacles equipped with UV protection are a better choice.

Anti-reflective: If you drive around at night, you would know the irritation to your eyes caused by headlights of other vehicles on the road. Most of it is the result of reflected light.
Not all light that reaches your lens passes through it; a significant amount of it is reflected back as well. The reflected light from the front of the lens can be a source of visual discomfort while reading, watching television or working on a computer. At the same time, light is also reflected off the back surface of lenses towards the eyes. This effect is especially pronounced under streetlights or due to headlights of other vehicles while driving at night.

By reducing reflections, anti-reflective coatings allow a greater amount of light to pass through, thereby increasing visual acuity. Anti-Reflective lenses therefore imply safer, more comfortable night-time driving by reducing glare from headlights, taillights and street lights. They also mean lesser eye fatigue caused by reflections from computer screens.

Blue Light Filter: Do you know that lighting devices such as LEDs and CFLs used in most of our homes today emit a radiation that is harmful to your eyes?

While the effects of UV radiation are well documented, our understanding of Blue Violet Light has so far been limited. However, in recent years, researchers have found that blue violet spectrum of visible light has the potential to cause damage to retinal cells. What is disturbing is the fact that Blue Violet Light is emitted by light sources such as LEDs and CFLs as well as by digital devices such as computers and smartphones. Given the increased usage of all these devices, what we are witnessing today is a much higher exposure to blue violet light. This makes the Blue Light Filter coating another essential aspect of eye protection.

Essilor offers this coating with select lenses such as Varilux® Digital, Eyezen™+ and Transitions® lenses, as well as Crizal Prevencia.

Scratch-resistant technology: There are two types of spectacle users – one who are very conscious about safe-keeping of their eye-wear; and others who indulge in rough usage of their accessories! Scratch resistance is a coating that is specially made for the latter. The hard protective coating helps provide a longer life to your spectacles by reducing chances of damage. Apart from increasing durability, it also prevents against scratches that reduce clarity of vision. Scratch resistance is specially recommended for children’s lenses.

Water Resistant coating: Anyone who has spent time wearing spectacles in the rain would know how rain water sticks to the lens and obstructs vision. With ordinary lenses, water spreads and sticks to the surface. This is especially problematic for children riding bicycles from school. A water resistant treatment repels water droplets away from the lens so that the water rolls into small droplets and slides off the lens with ease. By preventing water from collecting, the water repellant surface preserves clarity of vision.

Meet your optometrist to know which coatings are suitable for you. You do not need to select just one, different coatings can be combined together for multiple benefits in a single lens.