We're locked out. The room in which Steve Mann, the father of wearable computing, insists we do his interview is closed for the day, and Mann won't answer any questions until we get the door open. It's Tuesday afternoon, and I've come to the Augmented World Expo in Santa Clara, California to speak to the University of Toronto professor about wearable technology and the ubiquity of surveillance. But now, instead of searching for answers, I'm searching for a key.

Mann and I skitter through the conference halls, anxiously asking Expo employees if they can help us locate our mystical MacGuffin. After a few minutes of searching, Mann finds someone from his staff who can unlock the room. But first we have to help move Mann's hydraulophone--a musical instrument of his own design that uses water to produce sound.

At least we get that problem out of the way.

After stashing away the instrument, I discover why Mann is so eager to show me his space: The mystery chamber provides a showcase of Mann's wearable computing inventions over the years. With palpable excitement, he walks me through the various forms of headgear he has developed since the early 1980s--long before Google Glass catapulted high-tech headsets into the mainstream conversation.

With a doctorate from MIT in hand, Mann has spent the better part of the past 30 years adapting computers, screens, and optics into wearable contraptions. His first prototype was similar to Glass in that it featured a glass prism situated over the wearer's eye, though the setup was strapped to a helmet, and ran on a 9-volt battery.

The EyeTap digital eyeglasses he wears during our interview are the same ones he had on when he was attacked at a McDonald's in Paris in July 2012. These glasses are directly attached to his head, and can't be removed without special tools. Mann explains that this particular pair represented the fourth-generation of his work, and that he's already working on the fifth generation of EyeTap, which will add a second camera and support 3D augmented reality.

I ask him what he thinks of Google Glass, and Mann maintains the critical position that he's expressed in previous interviews.

"I don't think they got it right," he says. "I think it's a generation-one glass, and we're at generation five now. Glass strains your eye and your optic nerve because you're always looking above the eye. The generation-two glass [he motions to a pair of wearables similar to the ones he has on], which the eye itself is the camera, gets rid of those problems."

A representative of the University of California, Santa Cruz interrupts our interview to ask Mann about the IEEE International Symposium on Technology and Society conference he's hosting at the end of the month. So I wander over to a set of mannequins near the exit. One of these dummies is wearing a pendant containing a black sphere that, according to Mann, can project virtual objects onto the real world.

Thanks to a projector and camera inside the small black orb, the device's wearer can interact with augmented-reality projections using his or her hands. Mann says he plans to distribute the high-tech accessory to all 250 people who attend his conference--but he also jokes that half of them will just be empty shells, as many department-store cameras are.

I tell Mann about my experiences with Glass and how people keep thinking I'm using it to record their actions. I confide that Glass makes it easy to take pictures discretely without people being aware they're being photographed, and I question how the general public will react if suddenly multitudes of people have cameras strapped to their faces.

Mann tells me he quickly found out that people aren't happy when they think you're constantly pointing a camera at them. He then delves into his concept of "McVeillance," a state where people are under surveillance but aren't allowed to use their own cameras in return.

"People are afraid of change, so let me explain how this is a stasis," he says. "In the past 50 years, we've lived in a surveillance society--it's really the camera that freaks people out the most. Surveillance is a French word. Sur- means 'from above,' like surtax or surcharge, and veillance means watching. So surveillance means watching from above, like a prisoner being watched by a guard, or the police watching a suspect."

At this point, Mann gets into McVeillance, and how it relates to wearable computing.

"If we get rid of that 20th-century 'us versus them' paradigm, and just take the politics out, you're left with just veillance--which is just politically neutral watching," he says. "And I think that is very much like the old world. In the old days, the sheriff knew what everyone was doing, and everyone knew what the sheriff was doing. That's veillance. The police might say, 'Stop taking a picture of me,' but if you've got the [EyeTap] or Glass, they might not know whether you're taking a picture of them. It puts us on a level playing field because you don't know whether you're under surveillance."

The professor adjusts his digital eyeglasses while giving me a coy look, and, for a moment, I consider the possibility that he's been secretly photographing me. Now I know how Nick Bilton felt at Google I/O. Though to be fair, I was wearing Google Glass, and for all Mann knew I could have been photographing him. (I wasn't.)

Before I leave in search of food (and my train home), I ask Mann how he felt about being called a cyborg. He tells me he was annoyed that the media had been referring to him as the "world's first cyborg," as he finds the word to be rather vague. I ask him what word he would use to describe people equipped with wearable tech, and he replies, "augmediated."

"We can augment or diminish or modify or otherwise mediate our surroundings, and the computer serves as an intermediary between the real world and ourselves," he says.

Mulling over those parting words, I adjust my Glass and prepare for the long trip home. Veillance opportunities abound.