High Index Lenses

High Index Lenses with Anti-Fog Coating

After exploring your options, you may decide to select high index lenses for a number of reasons. Perhaps you have a strong prescription and want to reduce the distortion caused by standard lenses. Maybe the smaller profile of a high index lens will look much better in your desired frame style. Maybe your standard lenses were too heavy and you’d prefer the lightness of the high index material. Whatever the reason, your lenses are an investment and you want to take care of them.

Anti-Fog Coatings for High Index Lenses

It’s likely that you’ve opted for an anti-reflective coating for your lenses; with high index lenses it’s almost mandatory. But what about an anti-fog coating? Anti-fog coatings prove very useful if you:

• Live in a cold climate.
• Often experience humid conditions.
• Engage in exercise or sports activities that cause your body temperature to rise.
• Experience any conditions where you frequently move between variant temperatures.

Such conditions often cause a layer of moisture or fog to accumulate on your lenses. Constantly stopping what you are doing to wipe off your glasses can be real nuisance and many times can be impractical and dangerous. Motorcycle riders, for instance, need their hands to steer, brake, and throttle their bikes, and cannot pause to wipe down the glasses under their helmets. Police and firefighters often work outdoors in various weather conditions and move from heated areas to cold conditions; an inopportune layer of blinding moisture on glasses or safety glasses can prove deadly.

High index lenses will benefit as much from an anti-fog coating as standard plastic or glass lenses. Permanent factory-applied anti-fog treatments, however, are not always readily available for high index lenses, so options can be a bit more limited. A wipe-on, buff-off treatment creates a temporary deterrent to moisture and, although they need to be periodically reapplied, can be quite effective. One such well-recommended treatment is Cat Crap Anti-Fog.

As far as permanent coatings, Fog Free by Opticote is one coating that is compatible with high index lenses. Fog Free is thermally-cured to your lenses when they are cut and will not wear away. It will prevent water molecules from merging, which keeps them from coalescing into a visible layer of fog. Water droplets will still appear on your lenses, but in a more clear form, and not as a vision-obstructing haze.