Re: Gear Grinding 7: Really? This crap again?
Went to the optometrist for the first time in five years (was busy with work or would forget to schedule an appt for off days). Glasses were long over due to be replaced. There were micro-cracks in the lenses from the coating cracking. I could focus on things, but things appeared to be smudged to blur fine details.
Get told the best lenses for my prescription were High Index 1.67 lenses. They'll be just great for all the work I do outside. Lightweight and really thin. So I picked them up last week.
What they neglected to mention is that there is a prism effect that happens due to the ultra light/thin material used. Outside of the cone of vision, light starts to separate. Enough to where if I try to use my peripheral vision at all to see anything light colored (wide-screen computer monitor, papers and plans on my desk next to me) or on sunny days (any and everything that can reflect light), or bright lights at night, I can see the individual colors separate from their soruce.
And I can feel my brain melting when it's trying to figure out why "I can see everything in focus including my peripheral, but my peripheral isn't 'focused' right."
I've never had headaches from glasses before. The last pair of glasses (five years ago) was a move from glass to plastic in every pair of glasses I've worn since I was 7. (Weight of the lenses never bothered me.) That last optometrist I got ****ed at for not telling me how terrible Poly was for lenses because I had terrible tunnel vision from that ****. A new pair of lenses fixed that.
So, I try to explain to the optometrist what was going on Saturday. After having the glasses for a week. She had incredulously never heard of anything like that, and said the lenses measured to the specifications needed. Maybe they were ground slightly wrong. Which doesn'the explain why both eyes have the same problem. She said there wasn'the much that could be done except for sending them back and asking the lap to check them or tough it out and see if I could adjust to then (again, I've never had issues and any slight increase in prescription only caused a days adjustment. Not a week.
I said I'd try another week, but after two days I couldn't take it anymore. So they're ordering me 1.60 lenses.
The gear grinder is that in the Google-ing I did over the weekend to see if I'm missing a few chromosomes or others actually have this problem is that there IS a difference in the clarity of the material used for glasses.
Obviously glass is best, followed by old school plastic which is as thick as glass, then Trivex (a hardened plastic thinner than old school), high index material, and then the trash polycarbonate lenses.
But, optometrist push for thinner because the newer materials bend light better than the older thick material, thus less material is needed. That order goes high index, polycarbonate, trivex, old plastic, glass.
Apparently, I'm one of the rare few who actually notice the light bending (in my case separating) in high index glasses. There is a pair of lenses just a step below high index that has much better clarity (less of the prism effect) but it's a less popular material.
It's weird to explain.
https://en.m.wikipedia.org/wiki/Chromatic_aberration
http://www.2020mag.com/l-and-t/31816/
<img width=800 src=https://upload.wikimedia.org/wikipedia/commons/c/c1/Nearsighted_color_fringing_-9.5_diopter_-_source_image.PNG>
If I turn my head left and while focusing on this image, black lines appear between some of the colors as the colors shift over and bleed into other squares.
I can't wait for the new lenses to come in to fix it.
i hadn't seen that one before. Made me laugh
