Vole was supposed to flog the Integrated Visual Augmentation System (IVAS) based on its HoloLens technology to the US military, but reports showed that the field tests had not gone that well, with soldiers reporting that they felt sick after using the tech,

The US Congress has now denied the request to purchase 6,900 additional headsets for $400 million in a bill due to poor on-field results.

On-field testing of the headset had resulted in "mission-affecting physical impairments" for the 72 soldiers who wore them for three 72-hour periods across different combat scenarios.

The after-effects included eye strain, headaches, and nausea. For 80 per cent of infantry soldiers who experienced this discomfort, the symptoms appeared less than three hours after using the headset.

Although Congress has denied the $400 million funding request, it has still approved a $40 million budget for a new model of IVAS that resolves these issues. The new variant is expected to be more physically comfortable and sport better software with lower power draw.