6mo ago

Life Pro Tip: If you have an old retired pair of prescription glasses laying around, have one of the lenses ground down to snap into a keyring to fit in your wallet, or keychain, your choice.

Ignore the spikes LOL! But yeah, I keep that modded old lens in my wallet, in case I ever lose my glasses.

23 comments

Smart. Makes me wonder if it could be fun to have a big round prescription lens in a magnifying glass handle.
It's just a pity my eyes don't have the same Rx.
- My prescription is roughly -4.5, quite nearsighted.
  
  cries in -8.5
Ooh... clever.
You could probably grind it down yourself with a Dremel too. If you mess it up, it's not like you're losing something of value.
- I did it myself with a bench grinder actually. Also got the other lens ground down to fit another same size keyring even.
  Now, the plastic dust while grinding? Yeah, I probably should have worn a mask, but at least I made sure to do it outdoors.
  
  Do you do something to keep from scratching the keychain-lens into oblivion?
- Oh, since you're apparently the creator of this community, I failed to mention the facts that I had to do my best to identify the exact center of the lens before grinding it down.
  I did so by basically aligning an overhead light source against the reflection from both the front and back sides of the lens, then marked that spot with a sharpie marker, until I finished grinding anyways, then cleaned it off with rubbing alcohol.
  Maybe I should have mentioned such details in my original post, I'm not even sure if I'm describing it properly, but I gather you totally understand.
  Anyways, thank you for creating this community, and thank you for your skills and talents making frames and helping others with poor vision.
  I know you only recently started this community, I hope to see it grow! 👓
  
  Thanks!
  One easier and more precise way to determine the optical center - and rotational alignment too, which is important if your correction has a cylinder, but you didn't mention it so I assume yours doesn't - is simply to go to an optician and ask them to pop your lens in their lensometer and measure it. The lensometer will spot 3 dots on the lens. The center dot is the optical center and the line formed by the 3 dots is the horizontal alignment.
  A lot of opticians are located in malls or supermarkets, so it's simply a matter of taking your lens with you when you next go for groceries. It takes seconds to measure a lens and the optician won't charge you for it - and if they try, you'll know which optician never to patronize 🙂
You can buy credit card size fresnel lenses, pretty good magnification.
- Hah, already got one in my wallet, pretty handy at times. It also doubles as a way to start fires in the sunlight. 👍

23 comments