First, there were dashboard displays so drivers could see what was behind their cars as they backed up.
But that was far from foolproof. With the back of your car obscuring your vision, there's always a chance you'll miss something lurking unseen.
Researchers at Keio University, in Japan, are working on a solution: what if the back seat of your car were invisible?
The system they devised, the "see-through Prius", is being showcased at the 2012 Digital Content Expo in Tokyo this month. The driver of their Toyota Prius can literally look to the rear of the car and see what is happening on the street behind the car's seats.
The technology itself is not new; the concept of optical camouflage was developed a decade ago by Susumu Tachi, Masahiko Inami and a group of colleagues. The invisibility cloak they developed captured footage from behind the object and projected it onto the item. The cloak, embedded with reflective beads that shine light in specific directions, gave an illusion of partial invisibility. The video below demonstrates that technology.
The researchers have now modified the idea to create an additional safety feature in cars. While little information exists regarding the specific technology used in the Prius, it appears a display attached to the driver's headrest would project what was visible behind the car onto the back seat.
As Inami told a Japanese government publication, "the driver will feel like he's driving a glass car."
The question is: should you have a passenger in the backseat, would he or she also be rendered invisible?
See the aforementioned optical camouflage in action:
Photo: Keio University