When a person sleeps, do their eyes move or do they just stare straight ahead?

Answer

Depending on the stage of sleep your brother is in, his eyes will either be at rest or may be moving violently back and forth. Sleep is not a homogeneous process, and our brain activity and muscle tone differ according to the stage of sleep we are in. We distinguish between non-REM sleep on the one hand and REM sleep on the other. REM stands for Rapid Eye Movements, so fast eye movements. These are a basic feature of REM sleep and do not occur during Non-REM sleep.

Non-REM sleep and REM sleep alternate, and after every 70-120 minutes of non-REM sleep there follows a period of REM sleep of varying length, fairly short at the beginning of the night, about 5-10 minutes, at the end of the night. longer at the end of the night, about 20-30 minutes. In the adult’s sleep, about 15-20% of the total sleep is spent in the REM phase.

In a sleep study, in addition to brain activity, eye movements are also continuously registered with an electro-oculogram. For example, we can determine that during Non-REM sleep the eyes do not move, but that during REM sleep the eyes move very actively back and forth.