A team of scientists at the University of St. Andrews, Scotland has developed computer monitors that can detect when a person has stopped looking at them. At first glance, this may sound like some Orwellian micromanger’s dream, but its true purpose is to reduce distraction and increase productivity while taking the pressure off people whose jobs require staring at multiple displays for long periods.

The Diff Displays system uses multiple displays with a camera mounted on each screen to constantly scan the user, while an algorithm determines whether or not the user is looking at the screen. When the user looks away, the screen darkens. Then, when they return their gaze, the display highlights any changes that have occurred since the last time it was looked at.

The idea is that instead of trying in vain to watch three screens at once, the computer takes on the heavy lifting. Glancing away from one screen to another can make the viewer blind to changes that may have occurred during that glance. This is especially true of minor changes in a small bit of screen real estate, such a list of numbers. By fading out the screen when the user looks away, the Diff Displays can give prominence to the parts that have changed instead of the parts that remain static.

Currently, the St. Andrews team is studying four versions of the Diff Displays system.


As the name implies, FreezeFrame simply freezes the screen at the moment the user looked away. When the user looks back, the screen unlocks and the user can see the changes suddenly appear.


In PixMap, the screen darkens when not being watched and any areas that change brighten again to draw attention once the viewer returns their gaze.


WindowMap is similar to PixMap except that instead of just brightening an area where the change occurs, it brightens the relevant window.


Aura is a bit more subtle than the others. In this version, the changes on the darkened screen are surrounded by frames of varying brightness depending on the amount of change.

The St. Andrews team sees the Diff Displays system as having a number of applications, such as reducing distractions for office workers and helping air traffic controllers or nuclear power workers to maintain concentration and more easily keep tabs on things in a high-pressure situation.

According to the team, tests of the system have already shown that it reduces the number of times that a person looks away from the screens. Future plans include refining the system and seeking the optimum version for a given application.

The results of the team’s research was published in the Proceedings of the 18th ACM International Conference on Intelligent User Interfaces (PDF).

The video below shows the various versions of the Diff Displays system under development.

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