Have you ever wondered what it is that your eyes do while you are asleep? You would think that our bodies would be the most at peace when they are resting, but the truth is that your brain and eyes are extremely active when you are asleep. Learn what it is that your brain and eyes are doing during the most peaceful time of “day”.
When you go to sleep, your brain goes into five different stages. One of these stages is known as rapid eye movement (REM) sleep, with the other four stages known as non-REM sleep. During the stage known as REM sleep, your eyes will move very quickly in various directions. These movements of the eyes, also referred to as saccades, are the fastest-ever recorded movements made by your body. These movements can reach angular speeds of 900 degrees per second.
This stage of sleep accounts for roughly 25 percent of your sleep cycle as an adult and more than half of an infant’s sleep cycle. Due to the fact that sleep cycles repeat, the REM stage of sleep will occur multiple times in a night. Your sleep cycle will start with non-REM sleep, though you will enter into REM within the 90 minutes of dozing off. The first cycle of REM sleep will last roughly 10 minutes, and each phase will get a little longer. The last phase of REM will last as long as one hour.
During the REM sleep phase, many people will actually reach a temporary state of paralysis—your brain will signal your spinal cord to end muscle activity in your arms and legs, which is referred to as atonia. This process is believed to protect you from injury if you were to act out your dreams. While your body is relatively still during this time, you do still experience brain activity that is very similar to what you experience when you are wide awake. As a result, REM and vivid dreams are linked to one another. REM is often referred to as paradoxical sleep, which describes the strange active state that you brain is in when your body is immobile.
Though the specific reasons that your eyes are so active during REM are still up in the air, there are some clues that researchers have found. Some recent studies have been conducted on epilepsy patients that have shown that activity within the medical temporal lobes increases a quarter-second after the eyes moved. This has led researches to believe that mental imagery is changed by the brain during REM.
REM is directly connected with beneficial health effects and is part of the cycle that’s most linked with quality of sleep. The National Sleep Foundation reports that REM sleep benefits learning, memory, as well as mood. Therefore, when you have a lack of REM sleep, it can have negative repercussions on physical and emotional health in addition to brain functioning. It has also been associated with excess weight, migraines, and abnormalities in coping mechanisms and defensive responses.
While REM is a very regular and common part of one’s sleep cycle, it only tends to occur once you have reached a restful, or deep, sleep. Therefore, if you are not getting an adequate amount of sleep each night, then you will not be experiencing the beneficial effects that REM can give you. Moreover, sleep deprivation overall has the ability to impact eye health because your eyes replenish as you are sleeping, and in order to do so properly, you need to get five hours of sleep each night at minimum. Lack of adequate sleep can result in popped blood vessels in the eye, spasms, dry eye, as well as swelling of the optic nerve.
Adults should be getting somewhere between seven and nine hours of sleep a night, while kids should get between 10 and 11 hours of sleep—with babies and toddlers getting more. If you think that lack of sleep may be directly affecting your eye health and/or vision, don’t hesitate to give us a call at Performance Vision for additional information.