Google will flog its wearable tech Glass in a one-day offer of $1,500 before tax, in a bid to expand its pool of early testers.

On April 15 US residents will be able to purchase the device online, the spectacles having been confined to a limited number already enrolled in the Explorer programme.

The tech giant says that the number of new pairs would be restricted, but did not confirm a figure.

In a statement it adds: "Every day we get requests from those of you who haven’t found a way into the program yet, and we want your feedback too."

The scheme will go live on Tuesday at 1pm GMT, with the glasses now available in a variety of shades and frames.

Since being tested, Google’s wearable device has raised privacy concerns, prompting calls for a ban on the gadget.

The Android powered, internet-connected device operates on voice commands. Wearers can capture pictures, record video, and share content via email or social networking.

It also comes with Skype-esque video chats, weather reports and map directions, which will be displayed on a tiny screen fixed to the top-right rim.

Google will produce the eyewear at Foxconn’s Santa Clara facility in California, US.