[tenken]

Do you mean "High Index" lenses? ... I have strong prescriptions of -9.x and -11.x and I have had 1.66 index lenses. I've always noted to doctors light sources move around or float around alot with the lenses. I haven't necessarily noticed a difference with contacts (but I did see sharper with hard contacts) but my eyes cannot tolerate hard or soft lenses.

I have tried even higher index lenses, but anything above 1.66 and the distortions and optical aberrations get too annoying ...

[orthoxerox]

Yes, high refractive index lenses. -9 and -11 sound like actually good reasons to recommend them, at these levels of myopia lower index glasses should be noticeably heavier.

What I couldn't tolerate was specifically chromatic aberration. Every letter in this text box would have a yellow and blue fringe if my head was turned even slightly. And this would happen with every high-contrast border, like someone's t-shirt, a white car or a house against the sky.