You should use AYO with open eyes. We have designed AYO and AYO's light diffusion system in a way that it is very gentle and usually does not distract you in any way – so you can continue most of your daily routine seamlessly (e.g. working on the laptop, reading a book, cooking, etc.)
Using AYO with closed eyes will practically have no effect whatsoever since the human eyelids usually block more than 95% of the light, minimizing the effect of AYO.
AYO's light has been carefully tested and is fully certified for photobiological safety by the world renowned independent certification body TÜV Rheinland.