Tints

Tints can be used to make “Plastic” lenses in to sunglass lenses and are available in many colours. However, 1.67 and 1.74 lenses cannot be tinted as they already contain an antireflective coating to reduce “Power rings” which I will explain later.

Photochromic

Photochromcs are usually referred to as “Reactolite” which is a brand name for the glass variety or “Transitions” which is a brand name for the plastic variety.

Basically they do the same thing. These are lenses which are clear indoors but then “react” to UV (Sunlight) and “transform” into sunglasses.

Although they are not technically a coating and are manufactured this way a thought they were worth mentioning in this article.

NOTE: As photocromic lenses require UV to change, using them behind a car windscreen will not work as effectively as normal due to the windscreen filtering out some of the UV.

However, we have found that the glass reactolite works better than the plastic behind a car windscreen, but not as good as the plastic in normal conditions.

Polarized

Light reflected from surfaces like a flat road or smooth water is generally horizontally polarized. This horizontally polarized light is blocked by the vertically oriented polarizers in the lenses filtering our glare and allowing you to see below the water line. Available in grey or brown polarized lenses are ideal for fisherman and also for drivers.

Anti Reflective

Usually an anti reflective coating is referred to as an “MAR” (Multi Anti Reflective Coating). There are many benefits to an MAR. Firstly they are far more aesthetically pleasing as they reduce the amount of light reflecting off your lenses especially when having your photograph taken.

Other benefits include:-

• Reduced glare when driving at night• People can see your eyes and not a patch of light• Filters out radiation from computer screens• Reduces “Power rings” visible rings on the lens in high prescriptions which is caused by light constantly bouncing back and forth within the lens due to total internal reflection.

Spex4less provides MAR coated glasses for characters in Coronation Street to reduce reflections from studio lights and reflections of camera men in the characters glasses. Other suppliers include:-

 

 

 

Tags: Anti Reflective, Lens Coatings, Photochromic, Polarized, Tints, Transition Lenses, Transitions, UV

This entry was posted on Tuesday, July 24th, 2007 at 10:09 am and is filed under Lenses. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.