absolutely dark environment? - how to make it?

[mc1]

Hello guys,
do you know how to do absolutely dark environment in VR? F.x. in Tilt Brush I get not further than absolutely black surroundings with small white dots. However, I cannot get rid of the dots and it is clinically important to have it absolutely dark, so all visual cues are switched off. So far, only switching off the VR itself makes it the way I want it, but isn't that too dangerous for the VR to be switched on and off every 1min?
I need this dark scene between different parts of my testing exercises with my patients.
Thank you and best regards,
mc1

[HackPerception]

, this is not really possible with current VR display technology. What you're describing is called a mura - it is a byproduct of the fact that display panels are made out of millions of individual components working together to achieve a common image. When an HMD is manufactured, we calibrate the screen to be as even as possible and write that correction profile to the HMD's firmware (this process uses very specalized equipment). The Vive uses OLED displays which is able to achieve darker blacks than LCD technology (used in lower cost HMDs) but even then, mura effects can be very pronounced when the display is off simply due to how the displays work. Many other HMDs with LCDs will have a bright "backlight" effect that makes true black totally impossible.