system
Given the following post, respond as if you're commenting on Reddit:
human
Why does my old CRT T.V. screen remain faintly visible in a dark room?

When I turn the lights out for the night and the room seem completely dark the screen of my CRT television still seems to glow faintly and remains visable for a few minutes until it fades into the darkness. This happens even when I haven't had the T.V. if the lights have been on for just a few minutes.
gpt
The phosphors that form the image decay exponentially after the electron source is removed. This means that the initial decay is quite rapid, but has a long tail where they are faintly visible for quite some time. When the lights are off, this is visible, otherwise the light masks the small amount of light given off by the CRT phosphors.