A creation that initially started as a novel way to play video games has morphed into a tool for the blind. Tacit is a wrist-mounted device which tells the wearer about the vicinity of objects in difficult environments, according to its creator Steve Hoefer.

Ultrasonic sensors situated at the front of the device measures expanses from one inch up to 10 feet (2 cm to 3.5 m), Hoefer says, while mechanical rubber pads at the back of the device apply growing amounts of pressure on the wrist as operators move closer to an object.

In the beginning, the device was worn on the head and vibrations were used to inform the wearer of nearby objects, but that was speedily altered.

The inventor said he “kept crashing into things that weren't at head height and the vibrations drove me batty.” So he changed the technology and voila; he created a device that’s practical and affordable.

New Technology for the Blind - Tacit Sonar

It’s unpretentious, but it works. Powered by an average nine volt battery, the machine is easy to put together and inexpensive, with materials costing around $75.00. It is also light enough for everyday use and gives the wearer the capability to scan 360 degrees instead of just straight in front of them, a advantage blind people can truly use.

Robin Spinks, principle manager of digital accessibility at the UK's Royal National Institute of Blind People, thinks the technology has potential.

"Orientation and mobility are critical skills for a blind person's independence, education, employment and quality of life. Electronic orientation devices, such as Tacit, have the potential to enable individuals to move around independently and gain confidence," Spinks said.

Centered in San Francisco, creator Hoefer is presently working on reducing Tacit's size as well as refining its precision and streamlining its assembly.

"It's not perfect, but it works, and it can be better," Hoefer said.

It could easily be made about half the size, and the replaceable batteries should be replaced by rechargeables with a blind-friendly charging method -- either a wireless or magnetically-aligning power plug.

One of the biggest and best criticisms is that it is very difficult for a blind person to build their own. I hope to address that in a future version," he said.

Hoefer has released particulars of Tacit's materials, circuits and software on his Grathio Labs web under a Creative Commons license to take advantage of feedback and, with a bit of luck, improve the design.

"There are a number of improvements and changes left to be made. I'm curious to see what happens," he said.

Optimistically, with the assistance of other programmers and inventors, Tacit can become a life-altering tool for blind people across the globe.