Effects of a Monocular Laser-Based Head-Mounted Display on Human Night Vision

Head-mounted displays (HMDs) are expected to dominate the market of wearable electronics in the next 5 years. This foreseen proliferation of HMDs yields a plethora of design opportunities for revolutionizing everyday life via novel use cases, but also generates a considerable number of substantial safety implications. In this work, we systematically investigated the effect of a novel monocular laser-based HMD on the ability of our participants to see in low ambient light conditions in lab settings. We recruited a total of 19 participants in two studies and performed a series of established vision tests while using the newly available Focals by North HMD. We tested our participants' night vision after being exposed to different levels of laser luminous power and laser colors while using Focals, either with one or both eyes open. Our results showcase that the image perceived by the non-exposed eye compensates for the loss of contrast sensitivity observed in the image perceived by the laser-exposed eye. This indicates that monocular laser-based HMDs, such as Focals, permit dark adaptation to occur naturally for the non-exposed eye.