Sunglasses Lenses Materials and Coatings

Glass Lenses

Advantages:

  • Complete scratch resistance power without any scratch resistant coating
  • Exemplary optical clarity.
  • Anti-reflective (AR) coating is suitable to glass to a large extent

Disadvantages:

  • Well, a bit heavy -- twice the weight of plastic and polycarbonate lenses.
  • 25 to 40 percent thicker than plastic and polycarbonate 
  • Not shockproof
  • Needs to have a special coating for 100% UV protection.

Plastic Lenses

Advantages:

  • Lightweight  
  • Plastic lenses are adjustable to tints
  • Shatter - resistant  

Disadvantages:

  • 20 to 35 percent thicker than high index plastic lenses and polycarbonate.
  • Needs scratch-resistant durability.
  • Needs coating for 100% UV protection.

Polycarbonate Lenses

Advantages:

  • Safest lens material and impact resistant  
  • 20 to 25 percent thinner than plastic or glass  
  • Lightweight  
  • Blocks 100 percent UV rays  

Disadvantages:

  • Calls for scratch-resistant coating to last
  • Peripheral vision is a bit less clear in higher prescription powers.
  • More lens reflections than glass or plastic  

High Index Plastic Lenses

Advantages:

  • Lightweight - Between plastic and polycarbonate lenses in weight.
  • Thin  
  • Better peripheral optical view 

Disadvantages:

  • Calls for scratch-resistant coating for durability.
  • More lens reflections than glass or plastic lenses

Sunglasses Lenses Coatings

UV Coating

  • UV coating in glass and plastic lenses for 100% UV protection
  • Polycarbonate and high index plastic lens have the capacity to block 100 percent UV without any coating.

Scratch-Resistant Coating

  • Plastic, polycarbonate, and high index plastic lenses that have a relatively soft surface require a scratch-resistant coating.
  • Glass lenses have no need of scratch-resistant coating as glass naturally hard and scratch-resistant.

Anti-Reflective coating

  • Anti-reflective (AR) coating prevents reflections from the backside of sunglass lenses which can be a menace to clear and sharp vision.
  • Anti-reflective (AR) coating on polycarbonate and high index plastic lenses is essential as they reflect more light than glass or plastic lenses.

Mirror Coatings

  • Mirror coatings cut down the percentage of light that pass through the coatings by reflecting the light away. These coatings are on the front surface of the lenses and are blended with an underlying sunglass tint.
  • Mirror coatings sometimes as gradient coating provides maximum shading of sunlight as the sunlight is allowed to escape through the middle and lower part of the sunglasses.
  • Mirror coatings as double-gradient coating are used while snow skiing and other winter sports as they not only provide protection from the sunlight but also from the light that reflects off the snow.
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