Coatings on spectacle lenses.
By Optometrist Werner Fourie
So you went to your optometrist and had a comprehensive eye examination. Your refraction went well and you have your script for your new spectacles. Excitedly you also find your dream pair of frames you have been waiting for.
Now you need to decide on lens designs and add-ons, like coatings and tints. In this article I will focus on lens coatings and hopefully make the choice less daunting.
So what are lens coatings?
Lens coatings are enhancements that gets put on lenses to improve the performance of the lens and clarity of the vision. The more expensive your sunglasses or lenses are, the more likely they are to have one or more of the following enhancement:
Scratch resistant coating / hardening
This coating strengthens the lenses. Most lightweight lens materials (plastic, polycarbonate and high index lenses) have a relatively soft surface. This coating, as it suggests, makes it a little bit more scratch resistant.
Anti-reflective coating (ARC)
A percentage of light that passes through our lenses, gets reflected back of the lens surface, this reflection causes glare and can cause eye irritation. If you want people to see your eyes more clearly without obstructive glare, this lens enhancement in vital.
The reflection can also be present on the back surface of the lens, causing you to see your own eye reflection.
These anti-reflection coatings also improve visual quality while driving at night.
The anti-fog coating bonds to the surfaces of the lens absorbing moisture before fog forms.
Like most hydrophobic coatings on high performance sunglasses like Oakley, the coating weakens surface tension to assist run-off of water drops from the lenses. This coating helps repel grease, fingerprints and water, making cleaning the lenses easier.
As you can imagine, this coating blocks UV light from passing through the lenses, damaging your eyes. This is very important
Static electricity tends to build up on our lens surfaces attracting dust and pollen. This coating eliminates the occurrence of static electricity build-up making the lenses easier to keep clean.
Blue light neutralizing coating
Computers, tablets, GPS’s and smartphones all emit blue light, that with overexposure can cause eye strain, eye fatigue and even sleeplessness. These coatings neutralize the blue light and aid in comfort when working long hours on these devices.
Below image shows actor & singer, Bouwer Bosch, with his superior multi-coated Seiko lenses form The Eyewear Boutique
Below shows actress, Rolanda Marais, with her retro frame also with high end multi-coated Seiko lenses from The Eyewear Boutique.