[FoRK] Steve Mann: My “Augmediated” Life
eugen at leitl.org
Mon Mar 4 06:05:10 PST 2013
Steve Mann: My “Augmediated” Life
What I’ve learned from 35 years of wearing computerized eyewear
By STEVE MANN / MARCH 2013
Back in 2004, I was awakened early one morning by a loud clatter. I ran
outside, only to discover that a car had smashed into the corner of my house.
As I went to speak with the driver, he threw the car into reverse and sped
off, striking me and running over my right foot as I fell to the ground. When
his car hit me, I was wearing a computerized-vision system I had invented to
give me a better view of the world. The impact and fall injured my leg and
also broke my wearable computing system, which normally overwrites its memory
buffers and doesn’t permanently record images. But as a result of the damage,
it retained pictures of the car’s license plate and driver, who was later
identified and arrested thanks to this record of the incident.
Was it blind luck (pardon the expression) that I was wearing this
vision-enhancing system at the time of the accident? Not at all: I have been
designing, building, and wearing some form of this gear for more than 35
years. I have found these systems to be enormously empowering. For example,
when a car’s headlights shine directly into my eyes at night, I can still
make out the driver’s face clearly. That’s because the computerized system
combines multiple images taken with different exposures before displaying the
results to me.
I’ve built dozens of these systems, which improve my vision in multiple ways.
Some versions can even take in other spectral bands. If the equipment
includes a camera that is sensitive to long-wavelength infrared, for example,
I can detect subtle heat signatures, allowing me to see which seats in a
lecture hall had just been vacated, or which cars in a parking lot most
recently had their engines switched off. Other versions enhance text, making
it easy to read signs that would otherwise be too far away to discern or that
are printed in languages I don’t know.
Believe me, after you’ve used such eyewear for a while, you don’t want to
give up all it offers. Wearing it, however, comes with a price. For one, it
marks me as a nerd. For another, the early prototypes were hard to take on
and off. These versions had an aluminum frame that wrapped tightly around the
wearer’s head, requiring special tools to remove.
Because my computerized eyewear can augment the dark portions of what I’m
viewing while diminishing the amount of light in the bright areas, I say that
it provides a “mediated” version of reality. I began using this phrasing long
before the rise in popularity of the more widespread term “augmented
reality,” which usually refers to something less interesting: the overlay of
text or graphics on top of your normal vision. That doesn’t improve your
eyesight. Indeed, it often makes it worse by obscuring your view with a lot
of visual clutter.
Photo: Richard Howard/Time Life Pictures/Getty Images
GRAND DAY OUT: While a graduate student at MIT, the author experimented with
wearable computing systems, including this rather ungainly 1996 arrangement.
Click on image to enlarge.
For a long time, computer-aided vision and augmented reality were rather
obscure topics, of interest only to a few corporate researchers, academics,
and a small number of passionate hobbyists. Recently, however, augmented
reality has captured the public consciousness. In particular, Google has
lately attracted enormous attention to its Project Glass, an eyeglass-like
smartphone with a wearable display. I suppose that’s fine as far as it goes.
But Google Glass is much less ambitious than the computer-mediated vision
systems I constructed decades ago. What Google’s involvement promises,
though, is to popularize this kind of technology.
It’s easy to see that coming: Wearable computing equipment, which also
includes such items as health monitors and helmet-cams, is already close to a
billion-dollar industry worldwide. And if Google’s vigorous media campaign
for its Project Glass is any indication of the company’s commitment, wearable
computers with head-mounted cameras and displays are poised finally to become
more than a geek-chic novelty.
So here, then, let me offer some wisdom accumulated over the past 35 years.
The way I figure it, thousands of people are about to experience some of the
same weird sensations I first encountered decades ago. If I can prevent a few
stumbles, so much the better.
The idea of building something to improve vision first struck me during my
childhood, not long after my grandfather (an inveterate tinkerer) taught me
to weld. Welders wear special goggles or masks to view their work and to
protect their eyesight from the blindingly bright light, often from an
electric arc. Old-fashioned welding helmets use darkened glass for this. More
modern ones use electronic shutters. Either way, the person welding merely
gets a uniformly filtered view. The arc still looks uncomfortably bright, and
the surrounding areas remain frustratingly dim.
This long-standing problem for welders got me thinking: Why not use video
cameras, displays, and computers to modify your view in real time? And why
not link these wearable computer systems to centralized base stations or to
one another? That would make them that much more versatile.
I started exploring various ways to do this during my youth in the 1970s,
when most computers were the size of large rooms and wireless data networks
were unheard of. The first versions I built sported separate transmitting and
receiving antennas, including rabbit ears, which I’m sure looked positively
ridiculous atop my head. But building a wearable general-purpose computer
with wireless digital-communications capabilities was itself a feat. I was
proud to have pulled that off and didn’t really care what I looked like.
My late-1970s wearable computer systems evolved from something I first
designed to assist photographers into units that featured text, graphics,
video, audio, even radar capability by the early 1980s. As you can imagine,
these required me to carry quite a bit of gear. Nearly everybody around me
thought I was totally loony to wear all that hardware strapped to my head and
body. When I was out with it, lots of people crossed the street to avoid
me—including some rather unsavory-looking types who probably didn’t want to
be seen by someone wearing a camera and a bunch of radio antennas!
Why did I go to such extremes? Because I realized that the future of
computing was as much about communications between people wearing computers
as it was about performing colossal calculations. At the time, most engineers
working with computers considered that a crazy notion. Only after I went to
MIT for graduate school in the early 1990s did some of the people around me
begin to see the merits of wearable computing.
The technical challenges at the time were enormous. For example, wireless
data networks, so ubiquitous now, had yet to blossom. So I had to set up my
own radio stations for data communications. The radio links I cobbled
together in the late 1980s could transfer data at a then-blazing 56 kilobytes
A few years before this, I had returned to my original inspiration—better
welding helmets—and built some that incorporated vision-enhancing technology.
While welding with such a helmet, I can discern the tip of the brilliant
electrode, even the shape of the electric arc, while simultaneously seeing
details of the surrounding areas. Even objects in the background, which would
normally be swallowed up in darkness, are visible. These helmets exploit an
image-processing technique I invented that is now commonly used to produce
HDR (high-dynamic-range) photos. But these helmets apply the technique at a
fast video rate and let the wearer view the stereoscopic output in real time.
Video: Raymond Lo, Steve Mann, Jason Huang, Tao Ai
SMOKE AND MIRRORS: Realtime HDR (High Dynamic Range) video provides the
ultimate in welding helmets.
Welding was only one of many early applications for my computer-aided vision
systems, but it’s been influential in shaping how I’ve thought about this
technology all along. Just as welders refer to their darkened glass in the
singular, I call my equipment “Digital Eye Glass” rather than “digital
eyeglasses,” even for the units I’ve built into what look like ordinary
eyeglasses or sunglasses. That Google also uses the singular “Glass” to
describe its new gizmo is probably no coincidence.
Photo: Richard Howard/Time Life Pictures/Getty Images
TAKE ME HOME: Each of these street views shows a portion of what is seen
through the author’s computerized vision system when it’s running a
way-finding application. Click on image to enlarge.
I have mixed feelings about the latest developments. On one hand, it’s
immensely satisfying to see that the wider world now values wearable computer
technology. On the other hand, I worry that Google and certain other
companies are neglecting some important lessons. Their design decisions could
make it hard for many folks to use these systems. Worse, poorly configured
products might even damage some people’s eyesight and set the movement back
My concern comes from direct experience. The very first wearable computer
system I put together showed me real-time video on a helmet-mounted display.
The camera was situated close to one eye, but it didn’t have quite the same
viewpoint. The slight misalignment seemed unimportant at the time, but it
produced some strange and unpleasant results. And those troubling effects
persisted long after I took the gear off. That’s because my brain had
adjusted to an unnatural view, so it took a while to readjust to normal
Research dating back more than a century helps explain this. In the 1890s,
the renowned psychologist George Stratton constructed special glasses that
caused him to see the world upside down. The remarkable thing was that after
a few days, Stratton’s brain adapted to his topsy-turvy worldview, and he no
longer saw the world upside down. You might guess that when he took the
inverting glasses off, he would start seeing things upside down again. He
didn’t. But his vision had what he called, with Victorian charm, “a
Through experimentation, I’ve found that the required readjustment period is,
strangely, shorter when my brain has adapted to a dramatic distortion, say,
reversing things from left to right or turning them upside down. When the
distortion is subtle—a slightly offset viewpoint, for example—it takes less
time to adapt but longer to recover.
The current prototypes of Google Glass position the camera well to the right
side of the wearer’s right eye. Were that system to overlay live video
imagery from the camera on top of the user’s view, the very same problems
would surely crop up. Perhaps Google is aware of this issue and purposely
doesn’t feed live video back to the user on the display. But who knows how
Google Glass will evolve or what apps others will create for it?
They might try to display live video to the wearer so that the device can
serve as a viewfinder for taking pictures or video, for example. But viewing
unaligned live video through one eye for an extended time could very well
mess up the wearer’s neural circuitry. Virtual-reality researchers have long
struggled to eliminate effects that distort the brain’s normal processing of
visual information, and when these effects arise in equipment that augments
or mediates the real world, they can be that much more disturbing. Prolonged
exposure might even do permanent damage, particularly to youngsters, whose
brains and eye muscles are still developing.
Google Glass and several similarly configured systems now in development
suffer from another problem I learned about 30 years ago that arises from the
basic asymmetry of their designs, in which the wearer views the display
through only one eye. These systems all contain lenses that make the display
appear to hover in space, farther away than it really is. That’s because the
human eye can’t focus on something that’s only a couple of centimeters away,
so an optical correction is needed. But what Google and other companies are
doing—using fixed-focus lenses to make the display appear farther away—is not
Using lenses in this way forces one eye to remain focused at some set
distance while the focus of the other eye shifts according to whatever the
wearer is looking at, near or far. Doing this leads to severe eyestrain,
which again can be harmful, especially to children.
Photo: Ryan Enn Hughes
SEEING THE SOLUTION: The author wears his Generation 4 glass during one of
his lectures at the University of Toronto.
I have constructed four generations of Digital Eye Glass in the course of
figuring out how to solve this and other problems. While my latest hardware
is quite complicated, the basic principles behind it are pretty
Many of my systems, like Google Glass, modify the view of just one eye. I
find this works well. But I arrange the optics so that the camera takes in
exactly the same perspective as that eye does. I also position the display so
that the wearer sees it directly ahead and doesn’t have to look up (as is
necessary with Google Glass), down, or sideways to view it.
Getting a good alignment of views isn’t complicated—a double-sided mirror is
all it takes. One surface reflects incoming light to a side-mounted camera;
the other reflects light from a side-mounted display to the eye. By adding
polarizing filters, you can use a partially transparent mirror so that
whatever is presented on the display exactly overlays the direct view through
that eye. Problem No. 1 solved.
Illustration: Emily Cooper
MIRROR, MIRROR: Aligning the camera with the wearer’s eye requires an angled,
double-sided mirror. Light from the scene reflects off the front of the
mirror, sending it to the side and into a camera mounted near the wearer’s
nose. The images captured by the camera are computer-processed and then sent
to a special display called an aremac (“camera” spelled backward). The aremac
shown here uses a point source of light and a spatial light modulator to
project images off the back side of the mirror and into the wearer’s eye. The
use of a pinhole aremac ensures that the images remain sharp, no matter how
the eye’s lens is focused. Click on image to enlarge.
The second issue, the eyestrain from trying to focus both eyes at different
distances, is also one I overcame—more than 20 years ago! The trick is to
arrange things so that the eye behind the mirror can focus at any distance
and still see the display clearly. This arrangement of optical components is
what I call an “aremac.” (Aremac is just camera spelled backward.) Ideally,
you’d use a pinhole aremac.
To appreciate why a pinhole aremac neatly solves the focusing problem, you
first need to understand how a pinhole camera works. If you don’t, consider
this thought experiment. Imagine you want to record a brightly lit scene
outside your window on a piece of photographic film. You can’t just hold the
film up and expect to get a clear image on it—but why not? Because light rays
from every point in the scene would fall on every point on your film,
producing a complete blur. What you want is for the light coming from each
small point in the scene to land on a corresponding point on the film.
You can achieve that using a lightproof barrier with a tiny hole in it. Just
put it between the scene and the film. Now, of all the light rays emanating
from the upper-left corner of the scene, for instance, only one slips through
the hole in the barrier, landing on the lower-right corner of the film in
this case. Similar things happen for every other point in the scene, leading
to a nice crisp (albeit inverted) image on the film.
Few cameras use pinholes, of course. Instead, they use lenses, which do the
same job of forming an image while taking in more light. But lenses have a
drawback: Objects at different distances require different focus settings.
Pinholes don’t have that shortcoming. They keep everything in focus, near or
far. In the jargon of photographers, they are said to have an infinite depth
My pinhole aremac is the reverse of a pinhole camera: It ensures that you see
a sharp image through the display, no matter how you focus your eyes. This
aremac is more complicated than a barrier with a pinhole, though. It requires
a laser light source and a spatial light modulator, similar to what’s found
inside many digital projectors. With it, you can focus both eyes normally
while using one eye to look through the mediated-vision system, thus avoiding
It’s astounding to me that Google and other companies now seeking to market
head-wearable computers with cameras and displays haven’t leapfrogged over my
best design (something I call “EyeTap Generation-4 Glass”) to produce models
that are even better. Perhaps it’s because no one else working on this sort
of thing has spent years walking around with one eye that’s a camera. Or
maybe this is just another example of not-invented-here syndrome.
Until recently, most people tended to regard me and my work with mild
curiosity and bemusement. Nobody really thought much about what this
technology might mean for society at large. But increasingly, smartphone
owners are using various sorts of augmented-reality apps. And just about all
mobile-phone users have helped to make video and audio recording capabilities
pervasive. Our laws and culture haven’t even caught up with that. Imagine if
hundreds of thousands, maybe millions, of people had video cameras constantly
poised on their heads. If that happens, my experiences should take on new
The system I routinely use looks a bit odd, but it’s no more cumbersome than
Google Glass. Wearing it in public has, however, often brought me
grief—usually from people objecting to what they think is a head-mounted
video recorder. So I look forward to the day when wearing such things won’t
seem any stranger than toting around an iPhone.
Putting cameras on vast numbers of people raises important privacy and
copyright issues, to be sure. But there will also be benefits. When police
mistakenly shot to death Jean Charles de Menezes, a Brazilian electrician, at
a London tube station in 2005, four of the city’s ubiquitous closed-circuit
television cameras were trained on the platform. Yet London authorities
maintain that no video of the incident was recovered. A technical glitch? A
cover-up? Either way, imagine if many of the bystanders were wearing
eyeglass-like recording cameras as part of their daily routines. Everyone
would know what happened.
But there’s a darker side: Instead of acting as a counterweight to Big
Brother, could this technology just turn us into so many Little Brothers, as
some commentators have suggested? (I and other participants will be
discussing such questions in June at the 2013 IEEE International Symposium on
Technology and Society, in Toronto.)
I believe that like it or not, video cameras will soon be everywhere: You
already find them in many television sets, automatic faucets, smoke alarms,
and energy-saving lightbulbs. No doubt, authorities will have access to the
recordings they make, expanding an already large surveillance capability. To
my mind, surveillance videos stand to be abused less if ordinary people
routinely wear their own video-gathering equipment, so they can watch the
watchers with a form of inverse surveillance.
Of course, I could be wrong. I can see a lot of subtle things with my
computerized eyewear, but the future remains too murky for me to make out.
This article originally appeared in print as "Vision 2.0."
About the Author
A professor in the department of electrical and computer
engineering at the University of Toronto and an IEEE Senior Member, Mann
built his first computerized-vision system while he was still in high school.
“People thought it was a crazy idea back in the ’70s,” says Mann. Since then
he has constructed dozens of these systems and amassed more hours wearing
them than anyone else.
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