Hi-index lenses vs visual comfort

[sharpstick777]

Ange, next time, try 1.70 and critically compare chromatic aberration by looking at a string of LED Christmas lights in the dark and moving your head from side to side. Pay special attention to the color smearing with the blue and red lights. It will be less with 1.70, especially the red end of the spectrum.The blue will still smear some, just not as much as with other indexes.

Blue will always behave differently because short wave blue refracts through the eye to a different focal point from all other colors. This effect will happen even without correction.

[opti555]

I am responding to this old thread because I have a similar question as douglasrac posted earlier. "Visual comfort is inversely proportional to index of refraction?"

Has anyone heard of a low myope with an Rx around -2.25-0.50x180 OU having more "visual comfort" wearing a lower index lens such as polycarbonate or 1.6 index rather than 1.67 index or higher? Vision is clear at all indexes, except the lower index lenses provide the wearer with the most comfort when wearing the lenses. I can not seem to find an optical reason for why the lower index would be more comfortable for the wearer. Could it be related to the posterior base curve of the hi index lens?

[sharpstick777]

I am responding to this old thread because I have a similar question as douglasrac posted earlier. "Visual comfort is inversely proportional to index of refraction?"

Has anyone heard of a low myope with an Rx around -2.25-0.50x180 OU having more "visual comfort" wearing a lower index lens such as polycarbonate or 1.6 index rather than 1.67 index or higher? Vision is clear at all indexes, except the lower index lenses provide the wearer with the most comfort when wearing the lenses. I can not seem to find an optical reason for why the lower index would be more comfortable for the wearer. Could it be related to the posterior base curve of the hi index lens?

Yes, I would guess too that base curve is one of the factors. Polycarb excluded, lower materials usually have a higher ABBE value, esp 1.60.

[Tito]

1.7 index lens + optical best form base curve or Individualized aspheric /atoric + good optical & frame centered fitting + small frame + a good quality index matching AR = a highly satisfied customer

[Barry Santini]

Yes, I would guess too that base curve is one of the factors. Polycarb excluded, lower materials usually have a higher ABBE value, esp 1.60.

Regardless of lens form, best form or degree of CC compliance or FF optimization...

Lower abbe adds negative to the recipe. The more fragile the lens recipe, the more abbe negatively impacts taste.

B

[uncut]

I am responding to this old thread because I have a similar question as douglasrac posted earlier. "Visual comfort is inversely proportional to index of refraction?"

Has anyone heard of a low myope with an Rx around -2.25-0.50x180 OU having more "visual comfort" wearing a lower index lens such as polycarbonate or 1.6 index rather than 1.67 index or higher? Vision is clear at all indexes, except the lower index lenses provide the wearer with the most comfort when wearing the lenses. I can not seem to find an optical reason for why the lower index would be more comfortable for the wearer. Could it be related to the posterior base curve of the hi index lens?

I think that the visual "preference" is likely due to a wider field of view, and a desire not to be a head-turner at that power. This is often where prettier, and thinner doesn't win the beauty pageant!