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optics:how-to-order-glasses-online [2019/02/19 23:28]
trwnh
optics:how-to-order-glasses-online [2019/02/19 23:31] (current)
trwnh
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 # Clarity, peripheral vision, chromatic aberration # Clarity, peripheral vision, chromatic aberration
-- look for a high abbe value if you want more clarity, +- look for a high abbe value if you want 
-                             ​better peripheral vision, +  - more clarity, 
-                           ​and less chroma aberration. +  ​- ​better peripheral vision, 
-- consequently,​ the index actually doesn'​t matter for clarity; +  ​- ​and less chroma aberration. 
-  ​it only really matters for thickness! a high-index lens will +- consequently,​ the index actually doesn'​t matter for clarity; it only really matters for thickness! a high-index lens will typically lower the abbe value and therefore reduce clarity.
-  ​typically lower the abbe value and therefore reduce clarity.+
  
 # Aspheric lens # Aspheric lens
-- aspheric designs will change curvature gradually, +- aspheric designs will change curvature gradually, leading to flatter lens and better peripheral clarity. many high-index plastics might have aspheric designs to counteract the thicker ​edges.
-  ​leading to flatter lens and better peripheral clarity. +
-  ​many high-index plastics might have aspheric designs +
-  ​to counteract the thinner ​edges.+
   ​   ​
 # Distortion # Distortion
-- i ordered one trivex and one 1.67 high-index from zenni +- i ordered one trivex and one 1.67 high-index from zenni but both glasses had distortion at edges. 
-  ​but both glasses had distortion at edges. +- i think that's normal but i personally can't live with it, so i returned them and will be saving money to buy something with a better material. 
-- i think that's normal but i personally can't live with it, +  - lenscrafters advertises this as "hd lenses",​ which is also a manufacturing process-based technique. if that's anything like what i did in amman, then an eye scan will be required. the digital scan of your eyes is used to carve out much more precise lenses up to 0.01D instead of 0.25D increments.
-  ​so i returned them and will be saving money to buy something +
-  ​with a better material. +
-  - lenscrafters advertises this as "hd lenses",​ which is also +
-    ​a manufacturing process-based technique. if that's anything +
-    ​like what i did in amman, then an eye scan will be required. +
-    ​the digital scan of your eyes is used to carve out much more +
-    ​precise lenses up to 0.01D instead of 0.25D increments.+
   ​   ​
 # UV / Blue Light # UV / Blue Light
-- UV protection coating is kinda bullshit, +- UV protection coating is kinda bullshit, the lens material will typically block <380nm anyway 
-  ​the lens material will typically block <380nm anyway +- Blue light filters are even more bullshit, and can actively cause color shifts!
-- Blue light filters are even more bullshit, +
-  ​and can actively cause color shifts!+
  
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 RESOURCES: RESOURCES:
  
-https://​www.visioncareproducts.com/​high-index-lens-materials-past-present-future/​ +https://​www.visioncareproducts.com/​high-index-lens-materials-past-present-future/​ 
- +http://​www.mastereyeassociates.com/​eyeglass-lens-materials 
-http://​www.mastereyeassociates.com/​eyeglass-lens-materials +http://​www.trivexspecialist.com/​blog/​slimming-down-are-high-index-lenses-always-the-answer/​ 
- +https://​www.allaboutvision.com/​lenses/​how-to-choose.htm
-http://​www.trivexspecialist.com/​blog/​slimming-down-are-high-index-lenses-always-the-answer/​ +
- +
-https://​www.allaboutvision.com/​lenses/​how-to-choose.htm+
  
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