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Comment by zapstar | Hacker News Reader

Any chance you could describe chromatic aberrations? I’ve had some vision frustrations, and I feel like perhaps you’ve just described what I have. So did sticking with the thicker lenses help? Rather than the thinner? (I have a very high prescription as well, and I’ve always had the thinner lenses.)

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The aberration I see when I wear glasses are most obvious when looking at something like colored LED lighting - I can actually cleanly separate the red and blue components of a purple light into two separate images, for instance. More blended colors will just get the usual fringe.

That, along with the other severe distortion brought on by a -10 diopter, is why I mainly wear contacts now.

Rainbow fringes around light sources, particularly low-quality LEDs. Aberrations are minimal at the centre of the lens, but progressively get worse toward the edges (which is why contact lenses don't suffer from this problem). Driving at night became a nightmare, especially with LED headlights. I'd see cop cars out of the corner of my eyes everywhere when LED headlights would appear blue and strobe through a centre median. It didn't really bother me that much during the day though. For reference, I have diopters of -8.25 and -9.

I still have high-index lenses, but ones with a lower index of refraction and therefore a higher Abbe number. I don't remember specifically which material I have, but I think it might be high index 1.6 (index of refraction) with an Abbe number of 42. Chromatic aberrations are minimal enough with these lenses that they don't bother me much anymore (although still present).

For comparison, crown glass and CR-39 plastic have Abbe numbers of about 58, but will result in much thicker lenses at stronger prescriptions. Regular high index plastic lenses have the some of the worst Abbe numbers, and the higher index you go the worse it gets (Abbe of 32–36), but lenses can get very thin with high index 1.74. More on this at [2].

I've worn contacts several different times, but not only could I not get used to removing them from my eyes, I didn't like how much they worsened my close-up vision, and you can't just take off contacts like you can glasses.

This[1] comment by @mindslight on HN last year was a big help. In the end, I did have to switch providers when Costco didn't have any other material options (I got my glasses from Zehrs Optical in Canada). I payed about $325 altogether, but there was some sort of deal on so I don't know how it would be normally.

[1] https://news.ycombinator.com/item?id=19315769

[2] https://www.2020mag.com/article/does-material-abbe-value-inf...

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