Glasses and eyewear

A bit dated, but thorough and interesting testing methodology - as always with Project Farm.

This video is about luxury frame materials, not budget frames.

https://www.thinoptics.com/en-fi/collections/keychain

I don't own smart glasses but I am more and more interested in getting Even Realities G1 glasses because Even Realities seem to be open-source-friendly:

• They have a Github with a demo app and very complete technical details on how to communicate with the glasses via BLE.

• AugmentOS, an open-source smartglass operating system, supports those glasses.

Smart Caption is one of the free applications that come with AugmentOS. It seems to work really well!

Nice short video from Edmund Optics to visualize how lenses for astigmatism differ from uniform near- or far-sighted corrective lenses.

This is a very good guide that explains all the possible adjustments on a frame. But I will add two things he didn't mention:

• Some frames simply don't fit on certain faces. If you can't find any adjustment that works for you, you might have the wrong frames for you.
• If you overdo it, you'll eventually break the frames. Ask me how I know 🙂

Pretty good rundown, to which I will add the following regarding progressives:

• To minimize the distortion around the central intermediate zone, choose frames with small lenses that position the lenses as close to your eyes as possible. The closer they are, the larger the clear center zone will appear.

• Don't cheap out on the material and get the latest computer-controlled ground lenses, particularly if it's your first pair of progressives. If your optician offers an "interview" to personalize the position of the distance/near zones, use it. It seems like a gimmick but it really does help personalize the progressives to your activities.

  Progressives are difficult to get used to and it doesn't take much to make them unsuitable and difficult to live with. So stack the odds in your favor to make them work for you, even if it's more costly. If you can't get used to them, the entire cost of your new pair of glassess will be money down the drain and you don't want that.

• Give progressives a chance for at least 4 weeks, even if they seem to give you splitting headaches or nausea at first. Again, they're not easy to get used to. Once you are used to them though, they're a life-changer.

Funny and informative video, and the conclusion is unexpected.

8 minutes well spent if you want a primer on ophthalmic lens materials.

Incidentally, the Abbe number is why I always wear glasses with small lenses positioned very close to the eyes: chromatic aberration affects smaller lenses less. The shape and size of the lenses in the frames you choose is something to consider when you determine the kind of material you want the lenses made out of with your optician.

The video does mention that glasses made for children in the US are almost always made of polycarbonate to avoid litigation in case of a lens shattering during a child's activities. This is specific to the US: polycarbonate is almost never considered in any other country because it is a material with really poor optical properties.

If you're in the US, I urge you to resist fitting your child with polycarbonate lenses: a child's vision is still developing and it really deserves better. CR-39 is a minimum. Or if you have a bit more disposable, I personally recommend Trivex: it's impact-resistant too, but it's optically better, it's lightweight and it naturally has UV protection without coating.