The problem is that people are watching really scary films on their television whilst staying in bed – this means when they try to go to sleep then they are still in the same environment that they were in when they got scared in the first place.
The lack of displacement activity – eg not walking from the living room to the bedroom – means that the viewers mind is still literally inside the tv set where the horror was taking place. Then as the sufferer drops off to sleep they cannot actually remove their brain from with in the plasma. Leading to a troubled night of vision.
The problem has been called the Plasma Miasma by boffins and is affecting children as young as three years old. The science behind the phenomenon is difficult to comprehend but it all to do with tv and beds and brains. The rem cortex of the medulla becomes disassociated from the spinal stem – this leaves it float freely over several dimensions!
No government spokesperson has said anything on eh subject and it is unlikely that there is going to be any formal controls on the sale of TV beds because they are such favoured marital aids.