Glare from eyeglass lenses


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Glare from eyeglass lenses

  1. 1. H T T P : / / W W W . I R V I N E O P T O M E T R Y . N E T Glare From Eyeglass Lenses?
  2. 2.  Ever noticed glare or reflection from someone’s eyeglass lens? The person wearing these glasses and lenses may not realize it, but 8% of light that hits a person’s glasses induces annoying reflections and glare. This reflection and glare causes not only vision disturbance but also reduction in the person’s vision.
  3. 3.  Today there are special coatings that can be been applied to eyeglass lenses that virtually eliminate all reflection and glare. This is especially important with indoor lighting, streetlights, headlights, television and computer screens. With computer vision syndrome being so prominent and common, the need to eliminate glare on lenses is essential for eyewear when it comes to looking at a computer screen all day.
  4. 4.  The type of coating that is applied to eyeglasses to stop the reflection and glare is something that is referred to as A/R, anti-reflection or antireflective coatings. The Anti-Reflection coating is applied to the surface of lenses and other optical devices. The anti-reflective coating consists of a transparent thin film which contrasts the refractive index. The thin film layer helps change the wavelength and incident angle of the incoming light.
  5. 5.  The Anti-Reflective coating and interference based coatings were invented by Alexander Smakula in 1935. Alexander Smakula was working for the Carl Zeiss optics company at the time. The German military actually used the Anti-reflection coatings as a military secret during World War II. It wasn’t until 1930 though that Katharine Burr Blodgett and Irving Langmuir developed the organic anti-reflection coatings.
  6. 6.  This improves the efficiency of the eyeglass lenses since less of the incoming light is lost. The reduction of the glare and reflections helps improve the contrast of the image one is looking at. By adding the A/R coating one can reduce the stray light in the lenses.
  7. 7.  When one applies the coating to a new pair of eyeglasses, this helps enhance eye contact. Another benefit to the anti-glare treatment is the fact it enhances the appearance of your eyewear. Besides the benefits of the anti-glare coating, most A/R coatings include additional coatings that repel water and grease. This makes the lenses very easy to keep clean. The A/R coatings are usually suited towards higher-indexed lenses as they tend to reflect more light. It usually is cheaper to coat higher indexed lenses than that of low index glasses.
  8. 8.  The thin film anti-reflective coatings help to greatly reduce the loss of light in the many elements of the lenses. The quarter-wavelength of coating can eliminate all reflection in the eyeglass lens.