Coatings
Hardening/Anti Scratch
An anti-scratch or scratch-resistant coating is a film or coating that can be applied to spectacle lenses. This does not interfere with how the lenses function and does not affect vision, but creates a permanent bond with the lens that reduces the appearance of hairline scratches, which are common to spectacle lenses. Although an anti-scratch coating is not 100% scratch-proof, it helps to prevent minor scrates that can easily happen to regular lenses. These minor scratches can damage the surface of the lenses and impair vision. An anti-scratch coating acts as a protective layer thus making the lenses more durable.
Anti Reflective
Usually an anti reflective coating is referred to as an ‘MAR' (Multi Anti Reflective Coating). There are many benefits to an MAR...
- Far more aesthetically pleasing as they reduce the amount of light reflecting off the lenses - especially when having a photograph taken.
- For the same reason people can see your eyes and not a patch of light.
- Reduced glare when driving at night.
- Filters out radiation from computer screens.
- Reduces 'power rings' - visible rings on the lens in high perscriptions which is caused by light constantly bouncing back and forth within the lens.
- Provides UV protection.
- The anti-static component aiding lens cleaning.
Photochromic
These are lenses which are clear indoors but then ‘react' to UV outside and ‘transform' into sunglasses. They can also be referred to as ‘Reactolite' which is a brand name for the glass variety, or ‘Transitions' which is a brand name for the plastic variety. Something to be aware of is that different brands darken and clear at different rates. Most will darken more quickly than they clear and not all brands will clear completely and can be left with a slight residual tint!
As these lenses are activated by Ultra Violet light, they are at their best out of doors. Most modern car windscreens absorb a lot of the UV before it reaches your eyes and hence the lenses will not be as effective in the car. Generally, glass lenses tend to be more efficient the car, although plastic lenses tend to perform better in all other conditions.
Tints
Tints can be used to turn plastic lenses in to sunglass lenses and are available in a wide variety colours, most commonly brown, grey and grey/green. This is not available however on the 1.6 and 1.74 lenses, as they already include an anti-reflective coating.
Polarized
Normal daylight has vertical and horizontal components, however when reflected from a surface, such as a wet road or water, the horizontal components are enhanced and this is what causes ‘glare'. Polarized lenses are configured to block this horizontal component and only allow through the vertically polarized light. This greatly reduces glare, making them ideal for fishermen who want to see below the surface and also for drivers. They are available in both grey of brown.
Some of the brands we supply at Direct Spex...
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