The next thing we checked, there was light. The light around a sleeping person rarely gives him a sense of danger, so it can easily be integrated into a sleep without waking while sleeping. In one experiment, we removed the physiological parameters of 44 subjects while they were sleeping in the modified swimming goggles with built-in red LED. A few minutes after the start of REM sleep, when the subjects have had to plunge into it, we will briefly turn on the lights in the glasses. In the future, for the detection of REM phase, and lights on, we began to use the computer. This device was the first prototype of the 'Drimlayta', referred to in the following section.