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.

This is the prosthetic finger system from Point Designs. I haven't seen that one before. Unlike Naked Prosthetics' fingers, Point Designs' seem to address mainly the need of people with MCP joint-level or ray amputations of the hand. So kind of the same demographic as Ian Davis's fabulous prosthetic hand system, but much less complex.

They use a simple ratcheting mechanism that's designed to be washable, almost maintenance-free and able to withstand 150 lbs of pulling force:

Point Designs supplies an "impression kit" - basically a pot of quick-cure 2-part latex - to take a print of your residual hand and send it to them for fabrication of the socket. So presumably, if you have a handy friend to help your out, you don't need to visit a prosthesist and you can do it at home, potentially saving you money:

Finally, Point Designs offers free fingertip pads for the lifetime of the prosthesis and a 24-month warranty that covers manufacturing defects.

Not too surprisingly, I was unable to find any pricing information.

More worryingly, I was also unable to find any independent review or material apart from the company's own or their distributors'. So ultimately, I have no idea what those fingers are worth.

But they seem really cool so I figured I'd share.

I ordered a set of prescription lenses made of Trivex and mounted them this morning. Those things are light, that ain't no joke! The video shows the weight difference with the same lenses mounted in the same frames but made of regular CR-39 ordered from a no-name supplier (the Trivex lenses came from Hoya).

I've worn the Trivex lenses for a whole day and the weight saving does make a difference in comfort. If you're into ultralight glasses, I highly recommend Trivex lenses. They aren't the cheapest lenses but I find them well worth the premium.

Now, if only I could get those glasses into single-digit grams territory... I'm so close 🙂

Luxottica: the illusion of choice and what you're really getting when you spend hundreds of dollars on glasses.

This documentary was broadcast 13 years ago. Since then, Luxottica, the monopolistic Italian frames manufacturer, merged with Essilor, the largest ophthalmic lens manufacturer in the world. Today, EssilorLuxottica vertically controls 80% of the eyewear industry.

Here are more recent documentaries about EssilorLuxottica:

I wouldn't lump Github with Facebook or Twitter because, at its core, it's just a plain jane git server. If you stick to core features, you can exfiltrate your repos at any time in seconds and move them someplace else. And you can interact with Github's git server with open-source, fully documented tools.

It's the extended features Github offers that lock you in - the social media stuff and advanced git tools. So if you want to give Microsoft the finger, use Github only for basic services.

Me, I host all my repos there, and I use them also to host videos and as Linux distro repositories (apt and rpm) for my packages: I make it my duty to use up as many Microsoft resources as possible without paying them a dime and without giving them any edge to lock me in.

This is a pretty good summary of traditional glasses frame materials, to which I will add the following unconventional materials used in 3D-printed frames, that I have personally tried to wear quite extensively:

• PLA: lightweight, cheap, forgiving, ubiquitous, reasonably solid and durable, VERY easy to form - and deform - under moderate heat. Don't leave PLA frames on the dash of your car in the summer or you'll come back to a gooey mess. You can easily chemically-polish PLA smooth with acetone to make PLA frames very comfortable to wear on your skin for extended periods of time. PLA is a bioplastic made from plant material and is biodegradable, so it's a good choice if you're environmentally-minded. PLA has very low toxicity and is regarded as food-safe.

• PETG: a variant of PET - think frames made of the same plastic soda bottles are made of. Slightly stronger than PLA and a bit more tolerant of heat, but harder to polish smooth. Like soda bottles, it's not terribly environmentally friendly, but glasses frames use very little of it. PETG is also very low toxicity.Very comfortable to wear for a long time if you take the time to polish it.

• PVB: visually stunning. Can be polished to a shiny sheen in seconds - and destroyed just as quickly if you overdo it - with IPA. Clear natural PVB can be made almost transparent! Not that great mechanically, so only use it if you never abuse your glasses and you're after the aesthetics. Quite comfortable.

• Wood-plastic composite: I've only tried wood-infused PLA. It's substantially weaker than straight PLA and it's not terribly comfortable to wear for more than 12 hours, but it looks stunninly like real wood with a modicum of sanding with 400-grid sandpaper. If you like wooden items, this one is for you.

To start off, here's a tip to keep your lenses clean and free of scratches for as long as possible:

Don't let anything other than dedicated optical cloths touch your lenses!

That means never clean your glasses with anything other than a clean microfiber cloth or a disposable cleaning tissue.

If you don't have any at your disposal and you absolutely have to clean your glasses, use hand soap in running water and air-dry your glasses. Don't dry them with toiler paper or paper towels: they're a lot more abrasive than they appear and they will leave microscopic scratches on your lenses. Especially since most lenses are made of soft plastic nowadays.

I know it's hard to resist the temptation of blowing gently on your dirty lenses and cleaning them with your shirt, because you really want to remove that smudge of that piece of dirt that's been bugging you. But you absolutely need to resist the temptation: wait until you can clean your glasses properly. If you don't, the dirt that's already on the lenses will act as an abrasive and scratch them.

Me, I usually carry a disposable, pre-moistened wipe in my wallet in case of an emergency. But those things are expensive and I'm usually never far from a public bathroom with soap and water, so I never use it. But I have one if I need it.

The rest of the time, I buy lens cleaning fluid and microfiber cloths in bulk. I usually keep a bottle of fluid and a pack of microfiber cloths at work, and another at home. They last me and my family a very long time and ultimately bring the cost of always cleaning our glasses safely down to almost nothing.

My favorite brand is this one:

But really you can use any fluid to clean lenses or optical equipment. They're available in all supermarkets and opticians.

Welcome!

My name is Rosco. I've been a glasses wearer for the better part of 45 years, and an amateur frame maker for 20 years. I make frames mostly for myself but for others too on occasion.

I started making frames because I got tired of paying what seemed like insane amounts of money for a few grams of metal or plastic, and because it seemed incredibly wasteful to have to order new lenses each time I needed to replace my frames. So I started making my own and I learned a lot more than I wanted to know about the eyewear industry in the process.

Glasses are something a lot of people need, they're usually quite expensive and they're almost universally poorly covered by insurance companies and healthcare plans. What's more when you break or lose your glasses, it's always at the worst possible moment, and it can take weeks to get replacement glasses. So it pays to know how to get good deals on frames and lenses and how to care for them.

I wanted to share tips with other eyeglasses wearers, but I was surprised to find that, despite so many people wearing glasses, there doesn't seem to be any community. So I created this one.

I hope you will find it useful!