Japan has some pretty high-tech trains, but bumpy rides are still common. If you're squashed between dozens of commuters and gripping a strap with one hand while holding reading material in the other, turning the page as the speeding carriage lurches to and fro can be downright dangerous.
That's why NTT DoCoMo has developed a prototype tablet that you can control with your eyes. The "i beam" has a gaze-tracking function that frees your other hand so you can hang on to that subway strap, or, for instance, pull a suitcase around if you're walking through an airport.
On display at the 2012 Ceatec technology trade show outside of Tokyo, the i beam lets you turn pages with your eyes, scroll through a Web site, or select items like photos in a gallery. A green dot follows your gaze around the screen.
If you stare at a particular word in a text for one second, a definition will pop up. Touching the screen lets you zoom in and eyeball things more closely.
DoCoMo says the interface could also be used to play games where looking at things is part of the challenge.
The telecom giant developed i beam with Fujitsu and Tobii, a Swedish eye-tracking technology firm. It says its IS20 tracker is the most compact of its kind in the world.
It's the same technology that was shown off for the Windows 8 Gaze Interface earlier this year.
Still, the i beam is pretty large due to the two gaze sensors on the bottom half, and apparently is tricky to calibrate. DoCoMo hasn't released specs or a possible market date for the prototype.
Meanwhile, feast your eyes on this promo vid.