It is a normal physiological phenomenon that the eyes turn around when you are asleep, and all people will experience this change after they fall asleep. This is because sleep is divided into two periods, REM sleep and non-REM sleep, and these two cycles alternate during sleep, with about 4-5 cycles per night, each cycle lasting about ninety minutes. Patients in REM sleep are deeper in sleep, the brain wave frequency is faster and the amplitude is lower in this period, patients sometimes have faster heart rate and higher blood pressure, male patients sometimes have penile erection, this sleep stage is also called active sleep, most of the dreams occur in this stage.