Why we cut three moulds

We made three sizes. S, M and L — the hardware is identical, only the size differs.

It was not a convenient decision. Three sizes mean three front-frame moulds and three temple moulds, they mean splitting the stock three ways, and they mean everyone who orders has to make one more choice — and every extra choice loses some of them.

A single standard size is a reasonable approach

Most AI glasses today come in one standard size and rely on flexible temples to fit most faces. It is a reasonable approach: low tooling cost, simple inventory, a clean story to tell. Flexible temples really do cover a fair range. We chose a different path, and here is why.

There is only one dimension flexible temples can adjust — the angle the temples open to.

They cannot adjust frame width. They cannot adjust bridge width. They cannot adjust lens height. And those three decide where the glasses land on your face: too wide a frame slides down; too wide a bridge puts the whole weight on two points; too tall a lens catches on your cheekbone.

Ten minutes and a whole day are two different problems

Earbuds can be made in one standard size, because you wear them for a few hours and can take them out whenever you like.

Glasses are not that. They press on your nose and sit on your ears, from the moment you leave in the morning to the moment you get home at night. On that timescale three millimetres is not "a bit off" — it is the two red marks on your nose at the end of the day, and it is deciding not to take them with you next time.

A device you do not want to wear is worth nothing, however much it can do.

Size S is a separate matter

Size S is not size M scaled down. A child's face is not a smaller version of an adult's — the bridge is lower and narrower, and the distance between the eyes takes up more of the width of the face. Glasses shrunk proportionally slide straight down a child's nose.

And this is the size we had to get right anyway: the first children's AI glasses in the world that both photograph and record offline. If they are uncomfortable to wear, that sentence means nothing.

We did not economise on size L either

People with larger heads have never had much choice in eyewear — few styles to pick from, and the one they end up with is usually the one they can just about wear. Once two moulds exist, the marginal cost of a third is not as frightening as it sounds, and it serves people who normally have almost nothing to choose from.

The cost, stated plainly

The three sizes do not weigh the same: S is the lightest and L the heaviest. We are not going to cover three sizes with one number — the measured figure for each will be published before shipping.

And yes, you do have to make one more choice. Measuring your head circumference is the most accurate way, or send us the string of numbers printed inside the temple of the glasses you wear now and we will match it for you.