In practice, though, this editor had a hard time getting Glass to sit evenly for long periods of time. The right side (with all the equipment) tended to shift lower than the left. That does pose a bit of a problem, as Glass is supposed to be positioned such that the display is arranged high enough above your right eye that it isn't a distraction. Google's (incredibly helpful) Glass trainers will ensure you've got it perfectly positioned before you walk out the door, but keeping it there required constant fiddling.

Google Glass can and will fit over most eyeglasses, but rarely will it do so comfortably.

Overall, though, Google Glass is no more or less uncomfortable to wear than your average pair of glasses. The overly flexible nature of the band means it can be a bit tricky to put on without using both hands, but once positioned properly, it manages to be quite comfortable on both large and small heads. Those not used to wearing non-Google glasses will probably find the nose grippers uncomfortable at first, but those who are used to wearing glasses have their own sets of troubles ahead.

Google Glass can and will fit over most eyeglasses, but rarely will it do so comfortably. And, depending on the size and shape of those glasses, the eyepiece may be partially blocked by the frame. Finally, after letting dozens of people briefly try these on, a few with eyesight difficulties were simply unable to focus on the display at all. Before Glass goes mainstream, it will require an adjustable focal depth.

In fact, very little is adjustable in Glass. You can modify the wake angle (how far back you must tilt your head for the display to pop on) and enable or disable head detection, which automatically turns off the headset if you remove it. That's about it. You can't adjust volume levels or display brightness, can't disable WiFi or Bluetooth (both appear to be always on), can't re-arrange the application cards in the interface or set their priority, can't modify the default screen timeout length and you can't enable a silent or do not disturb mode -- though it could be argued that simply taking Glass off serves the same purpose.

Unfortunately, that act of taking off the headset can be rather inconvenient. That unbroken titanium band looks nice and provides flexibility, but it also means that Glass doesn't fold up like a traditional pair of glasses, so it won't dangle from the front of a shirt or slide easily into a pocket. That's made worse by the seeming fragility of the exposed refractive display, which we were told shouldn't be touched. Google thoughtfully includes a microfiber carrying case with a hard plastic insert to protect everything sensitive, but the resulting package is hugely bulky. Better bring your big purse.

Battery size is unknown, but battery life is known: it's poor.

Crack the case open (which we do not recommend) and you will find an aging TI OMAP 4430 processor, paired with 1GB of RAM and 16GB of storage (12GB available). Content will push to your Google+ account wirelessly by default, but you can pull it off through the micro-USB port if you like -- which is also how Glass charges. Battery size is unknown, but battery life is: it's poor. In what we'd consider average usage, reading emails and taking short pictures and videos, we got about five hours before the headset unceremoniously shut itself down. With lengthier filming of videos, which can be demanding enough to make your temple warm, we're sure you could deplete the headset's power reserves in a couple of hours. For a device that you'd want to set on your face and forget about, having to remember to charge it in the middle of the day is a definite disappointment.

Wireless and connectivity

When Glass was first introduced, many made the assumption that it would be wholly dependent on a smartphone (particularly, one of the Android variety) to function at all. As it turns out, that's not the case. The thing can function quite happily with a WiFi (802.11b/g) or Bluetooth data connection -- yes, even if that data is coming through an iPhone.

Glass is a fully independent device. This means you can leave your phone behind and walk around anywhere with WiFi without losing connection. But, that poses an unfortunate problem. Since Glass is independent, not pulling data through a dedicated app or the like, your wireless carrier will treat it just like any other tablet or laptop. If your current plan doesn't include Bluetooth data tethering, there's a good chance you'll have to pay to add it. That could make an already pricey device even more expensive to run.

Display

The display in Glass is an interesting one. When wearing the headset, you can look straight through the transparent part and barely even see it. It only minimally refracts the light that's beaming toward your eye. But, if you look at it from above, you can clearly see the reflective surface embedded inside at a 45-degree angle, forming the display your eyes see.

The panel itself is off to the right, built into the headset and beaming light into the clear piece from the side, which then hits that sliver of material and reflects into your eye. It's an interesting arrangement and the net result is, indeed, a glowing image that appears to be floating in space. Google says it's "the equivalent of a 25 inch high definition screen from eight feet away" and that sounds about right -- except that we're not sure about the high-definition part.

Google isn't talking specifics about resolution, but we do know that developers are advised to work with an array of 640 x 360 pixels. Individual pixels aren't immediately apparent, but the level of detail of the display doesn't come anywhere near your average, high-PPI smartphone display these days. You'll rarely see more than six rows of text at a time.

Colors, too, aren't exactly consistent and the whole thing similarly lacks the accuracy of a modern LCD or OLED panel. It almost has the look of an old-school, passive-matrix LCD, with its occasionally murky hues. And there's another problem, too: rainbowing. If you had the misfortune of owning a DLP television a few years back, you'll be familiar with the rainbow effect caused by the spinning color wheel. Moving your eyes side-to-side quickly on those sets created a dazzling, chromatic demonstration that would make a unicorn dizzy. The problem is less problematic here, but it is immediately apparent.

Finally, while contrast is reasonably good, seeing the display in bright sunlight can be a problem. That's doubly true if you use the included sunglasses attachment, which slots in between your eyes and the Glass display. In this way, Glass actually makes for nice sunglasses, but the insert has the effect of further reducing brightness and contrast of the display.

Setup and user interface

Setting up a Google Glass headset is trivially easy. Install the MyGlass app (which requires Android 4.0.3 or above) on your phone and tap a few choices to pair a new headset. Bluetooth will be enabled and a massive QR code appears. Hold that code in front of your face (while wearing Glass, of course) and, hey presto, Glass is now signed into your account.

It takes a few minutes to learn the basics, but once you do, it's easy to get around.

Once that's done you can use the app or go to Google.com/MyGlass to configure your headset. As mentioned above, setup is limited, but through a big, tiled interface you can select which contacts are accessible by name (only 10 are possible now), which of your Google+ circles you'd like to have the option of sharing content with, which Glass apps are enabled (Google+, Gmail, Google Now and Path are there by default) and which WiFi networks you want your headset to connect to.

Through here you can also bring up a Google Maps display of the current location of the headset, useful if it should be unwittingly removed from your face. That is disappointingly about the limit of the security features of Glass. You can also remotely wipe it, but there's no way of setting any kind of protection on the thing itself, meaning if you should set it on your desk and walk away, anybody can pick it up, put it on and start sending uncouth emails and pictures to your contacts.

Once you throw Glass on your face the interface is actually much the same, just flattened down to two dimensions. It's a bit like Sony's XrossMediaBar, in that you move left and right across a grid of options. Unlike XMB, you can't travel up and down. Instead, each icon in the row represents something and you tap to dive into it. Swipe downward to exit and jump back up a level, or to turn off the Glass display if you're already at the top.

You can activate the display in two ways: tilting your head up or tapping the capacitive touch portion on the side. The default display is a clock with "ok glass" written below. This is actually quite useful, as tipping your head up is a quick and easy way to check the time, though it'd be nice if you could turn off the "ok glass" bit. It's not that hard to remember.

If using the touch controls, you can swipe forward or backward. Swiping forward takes you back in time, with all recently captured photos and videos mixed in chronologically with emails, messages and notifications from apps. Swipe backward from the start screen and you'll get Google Now cards and, ultimately, a screen showing connection status and battery life. Flick your finger and you'll move one screen at a time, but slide it more quickly along the length of Glass and you'll cycle across multiple.

Tap on any of these options to bring up a context menu. For example, tapping on a photo or video lets you share or delete it. Tapping on an email lets you read more of it or reply. It takes a few minutes to learn the basics, but once you do, it's easy to get around.

Voice commands

If you're trying to operate in a hands-free mode, your key is "Okay, Glass." This initiating command must come before any other command, but it's worth noting that Glass itself must be enabled first. So, you can't just say "Okay, Glass." You have to tilt your head up or tap the side first. Only then is it willing to obey your commands.

What sort of commands? The most basic ones are "take a picture" or "record a video." Googling is also a very handy one, where you can say "Google, what's 20 percent of 30" to calculate a tip at dinner, or "what year was Brave New World published?" If you ask a simple question like the above, you're likely to get a result you can read on Glass. If you ask for something more detailed, like "Google a list of Tom Cruise movies," you'll only be able to read the first few results.

Hangouts are of course a big part of Glass, and you can start one by saying "start a hangout with" followed by the individual or Circle. Note that you sadly can't start a public Hangout, so make sure you build those Circles now. You can also call any of your earlier-designated contacts by name, assuming Glass is connected to your phone as a Bluetooth headset.

Glass knows the weather, too, defaulting to your current location, but letting you ask about other places, too. Do this enough and Google Now will thoughtfully include a persistent weather screen, which will slot in to the left. Navigation is also a big feature, with a command like "give directions to 125 State Street." Disappointingly, you can't use commands like "give directions home" and expect Glass to remember where your home is, neither can you get directions to your contacts. You'll have to speak the address, or do a business lookup by name or category. You can, for example, say "find me the closest pizza" and it will bring up a card showing a result, which you can tap on to call or get navigation directions.

There are some other miscellaneous commands, including translation ("say hello in Spanish"), photo search ("Google photos of Ferraris") and flight information ("what time does flight 123 depart from ALB?"). In general, all are received and understood without fault, but the broader voice recognition definitely leaves a bit to be desired, as we'll discuss shortly.

Taking photos and videos

Again, there are two ways to capture imagery with Glass: by voice (as described above) or by hitting the shutter release on the top-right of Glass. Click it once to take a picture, and whether you do it by voice or with the button, there's a momentary delay. This is important, as it gives you time to take your finger off, helping to stabilize things.

For video, hold the button down for a moment. By default, Glass captures 10-second videos, but if you want longer, you can tap on the side twice and it will record until you run out of storage -- or battery. Once captured, you can swipe forward or backward through what you've seen. Videos play automatically in this way, but with a few taps, you can either share them on Google+ (with the public, or with certain Circles) or delete them.

Sadly, though, you can't add any text. Anything shared has the hashtag "#throughglass," but nothing else to describe it. This does add a bit of mystery to your photo stream, but it would be nice if you could optionally speak a caption. Photos are synced with your Google+ account, so you can share them later at your leisure, but photos shared after the fact are rather less fun than those pushed online instantly.

Although, it must be said, the photos we shared often took minutes or sometimes even hours to get online. If your connection is anything less than very solid, you could be looking at a substantial lag. Larger videos will naturally take even longer.

Google Now

Google Now is an increasingly powerful part of the Android operating system, making recommendations based on where you go and what you do, and it's reasonably well-integrated to Glass. Weather is the easiest demonstration, showing an icon representing the current weather, along with temperature and high / low temps.

Get directions from Penn Station to a location and, once you get there, you're likely to find Now suggesting how to get back to Penn.

Now will also suggest directions based on where it's tracked you going. Get directions from Penn Station to a location and, once you get there, you're likely to find Now suggesting how to get back to Penn. It'll also throw up lists of nearby restaurants at dinnertime and, while suggestions are far from perfect, Now regularly surprises with its almost prescient understanding of what you're up to.

Of course, each of these screens can be interacted with. Tap on the current weather to get the forecast. Tap on a restaurant to call or get directions. Tap on a recommended destination to get navigation. All very helpful stuff, but we do wish we could manually pre-configure a bit more -- namely important locations and flights.

Navigation

Navigation is one of the best features in Glass. You can speak an address, find a business or tap on a Google Now suggestion and get turn-by-turn directions there. If you have the MyGlass app, it will also configure itself as capable of handling navigation, so you'll get the option of sending directions from your phone to Glass once you select a destination.

Directions look more or less as they do on an Android smartphone using Google Navigation. If you were hoping for a fully augmented reality experience, with a 3D arrow hovering in the distance over your next turn, that is sadly not the reality of the situation. But, it certainly seems like such a thing could be built in, as Glass does offer a degree of head tracking.

As with Google Nav, spoken directions are sent into your ear as you drive. However, unlike Google Nav on the smartphone, you can't disable that audio. Thankfully the voice used here is of the friendly, supportive type -- not the seemingly angry, short-tempered types that come along with some GPS units. Also, you're not able to choose navigation using public transport. It's driving, walking or biking for now.

Messaging

Messaging is an area of huge promise with Glass, but one that's a bit clumsy right now. When you get an email or a text, you'll hear a chime. To see the message, just tilt your head up. You'll see only the first few lines of the message, which is a bit unfortunate, but it's enough to know if you want to see more. If you do, it's two taps: one to bring up the menu, another to select "Read More." From there, it's another tap and a few swipes if you want to have the email read to you. You can also reply, reply all, archive or star the message.

It would be nice to be able to read an entire email just by tilting your head up and down to scroll.

An ideal use-case for this is getting emails read to you while in the car and then replying back by voice. Unfortunately, as it takes two taps and two swipes just to get to the "Read aloud" option, it's not exactly something you should be doing while driving. Even if you're sitting on the train, it would be nice to be able to read an entire email just by tilting your head up and down to scroll. The technology is in there, and hopefully Google will enable it eventually.

It's also worth noting that you cannot compose a new email. And, all responses must be performed by voice ... and all will have the text "Sent through Glass" inserted on the bottom, whether you like it or not. Speech-to-text is passable, but not good enough for anything other than a quick response. For example, it struggles to differentiate between things like "was" and "wasn't," which can definitely cause some unintended consequences, and complicated place names are a bit hit-or-miss. (Glass got "Schenectady" just fine, but "Azerbaijan" was heard as "our body John.")

If you speak slowly, clearly and avoid grammatical contractions you have a chance of sending a correct email. Should Glass hear you incorrectly, you have to cancel the entire message and start again. All the more reason to keep those responses short.

Searching

Google lets you search for lots of things, and indeed you can do the same through Glass. But, with the low-resolution display you're limited in terms of what you can receive. You'll basically get the "I'm feeling lucky" result for any query, which may or may not be what you're looking for and, even if it is, may or may not contain any actual information you want.

Asking "Google how many ounces in a cup" will get the answer spoken to you.

For example, say "Google Engadget" and you'll see the description of Engadget -- but not the page itself or indeed any gadget news. But, say "Google Paul Allen" and you'll get his Wikipedia result. Glass will even thoughtfully read the first sentence for you: "According to Wikipedia, Paul Gardner Allen is an American investor..." After that, you can swipe through a few pages of information about him, including a photo.

So, Googling is of mixed usefulness through Glass. Anything that hits Wikipedia is great, as is asking for simple math and conversions (asking "Google how many ounces in a cup" will get the answer spoken to you), but anything more complex may result in disappointment.

Hangouts

Video calling from a smartphone or tablet, where you need to hold that device up in front of your face, is a far-from-compelling experience that we generally avoid for anything longer than a quick "howdy." With Glass, we actually found it quite compelling. Now you can look straight ahead and see the face of the person (or people) you're talking to hovering out in space.

Of course, they won't see your face, which can be a good or bad thing depending on what you're looking at -- and how you feel about your face. We had a lot of fun trying impromptu Hangouts while walking through busy crowds or riding a motorcycle, and it definitely makes for a great way to show someone something if they're not able to be there in person. It's easy to envision touring a museum with someone who's stuck at home. It's also easy to envision museums not being happy about such a scenario.

However, the usability of this is hugely dependent on connection quality. You'll need to be on a solid LTE signal to have a hope of transmitting decent-quality video and audio without terrible lag. WiFi is obviously the better choice, where available.

Apps

The New York Times app is the most notable to be released to the public yet. It is very limited, pushing updates to Glass about every hour, more frequently if there's breaking news. Tap on any and Glass will read the headline and the first sentence of the article to you. And that's it. There's no "Would you like to know more?" prompt or any way to get to the full story.

We're incredibly eager to see what's coming next, as the potential here is, of course, huge. Right now, we'd be happy to post pictures straight to Twitter and Facebook.

Camera

The camera pointing out the front of Glass is a 5-megapixel unit capable of recording 720p video. Resulting photos range from very good to very poor, largely depending on the amount of light available. On a bright, sunny day, Glass can capture some genuinely good shots, with bright, accurate colors and good contrast. In mediocre lighting, shots can be acceptable, but they very definitely fall into the "mediocre cameraphone" quality, with murky colors and often subtly blurred results. In low light, photos will likely be a mess. No Ultrapixels here, folks.

One thing that helps is that the camera waits a few seconds after you press the button to capture the shot. This could theoretically mean you miss some incredibly fast-paced moment, but more helpfully, it gives you time to take your hand from the headset and steady yourself before the shutter fires. Annoyingly, though, the way the shutter button pokes out of the top of the frame, you're more likely than not to take a picture when you set Glass down upside-down. We had dozens of unintentional upside-down photos clogging our storage.

After the picture is taken, it's shown to you for a few moments, a useful feature since there's no viewfinder at all and the angle of the picture won't line up exactly with where you're looking. Also, if Glass isn't perched perfectly on your face, there's a good chance the picture will be at an angle, meaning you may need to cock your head one way or the other.

The same can be true for video capture, but here you get a real-time view of what's being recorded. Quality is generally quite good, again largely dependent on the amount of available light. You do have to be careful to be steady while walking, but in general we were able to capture smooth video without too much trouble. The biggest issue? Remembering not to nod when having a conversation with someone.