Types of Smart Glasses

“Smart glasses. XR/AR/VR/MR. Interfaces. Cameras on faces. Dinosaurs on kitchen tables. Tony Stark’s EDITH glasses. Glassholes. The starship enterprise. What is going on?”

In this article (which is a work in progress) I will lay out the current state of the art in smart glasses and products that are available now.

This article will very much focus on technology. We assume that you’re on board with the huge potential of smart glasses to enhance our lives in a fundamental way. It’s worth noting that this article is worthless without use cases – all of the headworn tech in the world will never be useful without use cases, features, apps that run on them and that the user interacts with in some way. If you want to understand the potential of smart glasses, checkout my massive list of the best smart glasses use cases:

The Big List of Smart Glasses Use Cases

We’re also going to focus on products that you can buy today. There are a plethora of announcements, rumours, and prototypes in production, but it’s easy to make a cool (and fake) demo video, and very hard to get a device to production. Our discussion and examples are focused on what exists now.

Smart phones don’t require a lot of categorisation. There’s iPhone and Android, and not much else. Other than the software, all iPhones are and Androids are relatively the same thing – a 6inch thin rectangle with nearly identical suites of functionalities and human-computer interfaces. For smart glasses, though, this space is young enough that we are seeing a wide range of functionalities from different glasses.

This ambiguity in the term “smart glasses” leads to a host of problems – consumers think new products can do things they can’t, business executives get mad when engineers can’t make tiny HD AR displays because “Facebook did it” (they didn’t), and generally confusion ensues. Many arguments have been started with a claim “but those aren’t *real* smart glasses!”. In an effort to help you, ourselves, and the field come together, we have formed categories of smart glasses based on their technology, capabilities, and intended use cases. *We use the term “smart glasses” broadly to mean any pair of glasses with a computer in them.* Yes, this is obvious to some and heresy to others, but this is how the term has come to be used, and it can serve as a catchall term for any computational glasses form factor device.

Note that this categorization is for what exists now, in late 2022/early 2023. As with a lot of general purpose computing hardware, we expect the device types of converge in the future into the “ideal” suite of form factor and capabilities.

For a device to be considered smart glasses, two things must be true:

  1. These *must* be a glasses form factor. Head bands, hats, anything with a band over the top of the head, etc. are not HUD smart glasses. The inclusion in this category of headsets with back bands like the MagicLeap 1/2 is debatable, but anything that requires a back strap probably won’t make it in the weight category.
  2. They must have an embedded computer within the glasses.

This is the classical device that you think of when someone says smart glasses. This category is seperate from “AR/XR” glasses specifically because, with today’s technology, visual information in an all-day form factor is becoming reasonable in the form of a limited field of view (FOV) heads-up-display (HUD), but is still *not* reasonable for a true immersive augmented reality (AR) experience [Snap CEO Spiegel on AR tech]. The HUD Glasses category focuses on glasses with displays, but limited resolution, FOV, brightness, etc. in order to achieve a form factor that is comfortable in terms of physical wearability and socially acceptance.

These glasses often have all of the same features of audio glasses and camera glasses, but also with a display.

In order to be conceivable for long term wear, these smart glasses must be under 100grams, and realistically must be <= 70grams.

What makes them HUD glasses is the presence of a display. Low resolution and low field of view are expected at this point in time in order to achieve a form factor, power, thermal, etc. characteristics that is reasonable for long periods of use (see Avegant, JBD, Lumus, etc.). This is, surprisingly to some, not actually a large weakness, and many of the most important smart glasses use cases don’t require highly immersive AR overlays, and simply rely on heads-up information access [The AR Show – Paul Travers].

In order to provide useful information on the display glasses must either have on-board processing or wireless communication to an external device which can perform the processing and provide the information to be displayed.

  • Vuzix Blade
  • Inmo Air
  • Vuzix Shield
  • Google Glass

Regarding displays, there are two general categories – monocular and binocular. Monocular means the display is only shown to one eye, and binocular means it’s shown to both eyes.

There are a vast array of technologies that come together to form the opto-electronic engines that drive smart glasses displays. A description of all of these is outside the scope of this article. See https://kguttag.com/ and https://spie.org/Publications/Book/2559303?SSO=1 for more information.

We will mention that while birdbath optics are commonly used in AR glasses, they are too big, bulky, and heavy for all-day wearable HUD smart glasses. The best HUD smart glasses today normally utilise diffractive or reflective wave guide lenses which receive light from a microLED or microLCOS display.

Glasses that focus on audio provide uses like intelligent assistants, voice command, listening to music, receiving notifications, etc. The lack of a display allows for significantly simplified electronics, which have allowed for a few recent audio smart glasses products which are nearly impossible to tell they aren’t real glasses.

  • Huawei Gentle Monster
  • Bose Frames
  • Amazon Echo Frames

Camera smart glasses have a camera, like many other smart glasses, but camera glasses focus on the camera as the main use case. These glasses are intended almost exclusively to take use of the camera for point-of-view (POV) video and image capture.

  • Snap Spectables (1.0, 2.0, and 3.0).
  • Ray Ban Stories
  • Thousands of “spy glasses” and “recording glasses” from electronics markets (e.g. Alibaba/express)

These glasses create immersive experiences that don’t just complement physical reality, but extend, enhance, morph, manipulate one’s experience of physical reality. AR is a technically difficult field, and all existing products are still large, bulky, and power hungry [see Nreal, Magic Leap, etc.].

As opposed to HUD glasses, AR glasses must achieve a perfect alignment between the display and the real world. This creates challenges of alignment, focus, color matching, low-latency, computation, and much more that makes AR notoriously difficult (and hence not yet achieved).

  • Nreal Light
  • ProEyes 3e
  • Magic Leap 1
  • Not Hololens – Hololens does not follow a glasses form factor

Smart glasses designed specifically for the health, wellness, performance, and fitness of the user fall into this category. While these glasses might sport any mix of display, audio, camera, sensors, etc., what sets them apart is their singular focus on health and wellness. Like how some people use smart watches with full applications capability and some people prefer simple “health tracker bands”, health and wellness glasses are a killer-app for smartglasses whose possible slim form factor and lack of privacy-issue-raising environmental sensors (i.e. camera) allow for easy adoption into daily life.

  • BlueberryX fNIRS Glasses
  • Smith + InterAxon LowDown Focus EEG Glasses

These glasses are designed to do what glasses have always been meant to do – help us see. Some opthalmic glasses work to improve

  • programmatic prescription
  • active light therapy
  • magnification
  • automatic tinting

There are some glasses which are made for a very specific reason, and they only perform that single use case. These usually take advantage of HUD Smart Glasses with sensors and display for applications like

  • Audio-speech to text glasses for the deaf
  • Optical-text to speech glasses for the blind
  • Extreme HD magnification to restore sight to blind
  • TCL AR Glasses
  • Vuzix Shield
  • Top Smart Glasses Devices: Vuzix Blade, Inmo Air, NuEyes Pro3e, Nreal Light
  • Top Software Companies: Google, Emex Labs, Teamviewer, Gemvision
  • Top Current OEM Companies: Vuzix, Dispilex, Lumus, Kopin, JadeBird
  • Top Current Device Companies: Vuzix, Nreal, Google, Snap, Emex
  • Top Future Device Companies: Meta, Apple, Inmo, Xiaomi

About this article

This article was written by Cayden Pierce with help from the H20 Smart Glasses Commmunity.

This article is a constant work in progress. Think we got something wrong or missed something? Send me an email with edits to: cayden@emexwearables.com