What do your eyes do while you sleep?

The eyes are the windows to the soul, but only during waking hours. When you're asleep, they stay closed, blocking out dust and other types of debris. Your eyelids also act as built-in window shades, keeping that pesky sunshine from waking you up before you're ready. So, what do your eyes do while you sleep? We have the answer.

Eye movements during sleep

The answer to "What do your eyes do while you sleep?" depends on which phase of sleep you're in: rapid eye movement (REM) or non-rapid eye movement (NREM). Before you start humming Shiny Happy People, you should know that REM sleep is associated with dreaming. What is REM sleep? It's the phase characterized by increased brain activity and rapid movements of the eyes.

Why do eyes move during sleep?

Until recently, researchers didn't know what caused these rapid movements. Now scientists from University of California, San Francisco believe eye movement during REM sleep corresponds to events taking place in a virtual dream world. In other words, if you're dreaming about being chased by a dragon, your eyes are probably trying to figure out where the dragon is and identify an escape route.

Stages of NREM sleep

NREM sleep is broken into three stages. Stage 1 goes by in the blink of an eye, lasting just 5 to 10 minutes. During this stage, your muscles relax, your eye movement slows down, and you may feel like you're falling through space. This is known as a "hypnic jerk," and it's nothing to worry about.

Stage 2 of NREM is when your body prepares for deep sleep. Your eyes stop moving, your body temperature decreases, and your heart rate slows. Your muscles also go through a cycle of contracting and relaxing. Finally, you fall into a deep sleep.

During stage 3 of NREM, your eyes and muscles don't move at all. Your brain produces very slow waves, making it difficult to wake you up. This is when your body engages in a little self-care, repairing damaged tissues, strengthening the immune system, and building muscle and bone.

The role of REM sleep

REM sleep begins about 60 to 90 minutes after you fall asleep. During this sleep phase, your body experiences the following changes:

• Muscle relaxation
• Increased blood pressure
• Faster heart rate
• Increased brain activity

During REM sleep, your body doesn't regulate temperature as efficiently as it does during the day or during NREM sleep. That means you won't get as much REM sleep if you keep your air conditioner set to "Arctic" during the summer. 

Even though you don't sleep as deeply during REM, this phase serves an important purpose. During REM, your brain processes all the new information you learned during the day. It commits that information to your long-term memory, locking it away for future use. REM sleep also regulates your mood and helps you concentrate when you're awake.

Due to the heightened level of brain activity that occurs during REM, you have vivid dreams during this stage of the sleep cycle. These dreams are so intense that they often seem like they really happened. You might be disappointed to wake up and find out you didn't really win a million dollars or find a cure for cancer. Then again, if you have a bad dream, you may be relieved when you wake up and find out it wasn't real.

Why do your eyes roll back when you sleep?

If your partner tells you that your eyes roll back when you sleep, don't panic. As you fall asleep, your muscles relax. In some people, this loss of muscle tone causes the eyes to roll back, instead of staying in position. Your eyes may also roll back during REM sleep, especially if you have an annoying encounter in the dream world.

Enhancing REM sleep

Wondering how to get more REM sleep? You're in luck. In most cases, a few simple lifestyle changes are all it takes to increase the length of each REM cycle. The first step is to develop a sleep routine. If you go to bed at 9 p.m. one night and 3 a.m. the next, your body never has a chance to adjust. Do your best to wake up and go to bed at the same time every day.

Routine is also important when you're getting ready for bed. Instead of blasting Lizzo and partying like it's 1999, take a warm bath, read a book, or listen to some relaxation tracks on your favorite music streaming service. If possible, meditate or find other ways to relieve stress.

Find the perfect pair of contacts

Eye health is always important, whether you're tackling your to-do list or getting a little shuteye. The right contacts help you keep your eyes as healthy as possible. 1-800 Contacts makes it easy to find your prescribed brand of contact lenses.

Frequently asked questions

How can I increase my REM sleep duration?

You can increase your REM sleep duration by developing a sleep routine, replacing worn-out pillows, and avoiding alcoholic beverages at night. You may also benefit from avoiding daytime naps and finding ways to relax before bed.

What should I do if I have concerns about my sleep patterns or eye movements during sleep?

If you have concerns about your eye movements during sleep, see an eye care professional. Your primary care provider is also a good resource if you're concerned about your overall sleep patterns.

Should I be concerned if my eyes open while I am sleeping?

Having your eyes open while sleeping may be a sign of several medical conditions, such as nerve problems, bulging eyeballs, and weak eyelids. If you're concerned, schedule an appointment with an eye care professional.