How Does Sleep Affect Your Eyes?

Sleep is restorative for all parts of the body, including cognition and immune function. Getting enough shut eye will keep you alert, more able to fight off infection and give your eyes the moisture and rest needed to perform at their best.

We have a look at how sleep can impact your eyes and give you some tips on how to sleep more efficiently.

What happens to your eyes when you sleep?

During stage 1 of sleep, our eyes roll slowly, opening and closing. During stages 2-4 you are in deep sleep and your eyes are still. There’s a stage of our sleep cycle called rapid eye movement (REM). During REM sleep, our eyeballs move rapidly behind our eyelids and our bodies become more still. It’s during this stage that we dream. It’s not known why our eyes move so much during this stage, but some believe it could be because we are watching the scenes in our dreams.

Why do my eyes hurt when I don't get enough sleep?

Your eyes can feel strained, dry and itchy the day after not getting enough sleep. Lack of sleep can cause eye strain, burst blood vessels and dry eye.

Our eyes go through a lot during the day. From the moment you wake up to the moment you go to bed, your eyes are always working. It's important for them to get enough recovery time when you're asleep. Getting enough sleep will give your eyes moisture throughout the night so that they can function properly when you wake up.

What are the risks that come with lack of sleep?

As well as causing dark circles and puffy eyes, lack of sleep also poses a threat to our overall eye health and causes the following risks and side effects:

• Eye twitches
• Eye spasms
• Light sensitivity
• Blurred vision
• Glaucoma
• Dry eye diseases
• Vision loss
• Eye infections

Sleep apnoea and your eyes

Sleep apnoea is a serious sleep disorder where breathing stops and starts frequently. It can have a severe effect on your eyes and is a risk factor for glaucoma which causes vision loss.

Symptoms of sleep apnoea can be spotted during an eye exam and include changes in your vision, eyelids or retina. These symptoms are reversible when sleep apnoea is treated.

Why do we need to close our eyes to sleep?

There are many reasons why we need to close our eyes while we sleep. Closed eyes block out light, so that the brain is not kept awake. Closing our eyes to sleep also prevents dry eyes as our eyelid helps to spread tears across the surface of our eyes while we sleep.

Sleeping with your eyes open is called nocturnal lagophthalmos and people who sleep with their eyes open usually have damage to their facial nerves or their eyelids.

How to have a good night’s sleep?

We need at least 5 hours of sleep per night for our eyes to fully recover from the day and 7-9 hours would be ideal. If you have trouble sleeping, here are our top tips on how to get more sleep each night and avoid sleep deprivation:

• Get as much daylight/sun exposure during the day as you can - this will increase the quality of your sleep in the evening, just ensure you wear UV protective eyewear.
• Limit your exposure to light (and screens) at least 2 hours before bed - the blue light from your screens can stop you from sleeping by tricking your body into thinking it’s still daytime and you should be awake
• Wear blue light glasses - these help filter out some of the blue light that emits from digital devices such as your mobile phone or laptop and can help to provide you with a better quality of sleep
• No matter what time you go to bed, wake up at the same time every day (as much as possible) - having a consistent bedtime will help you to sleep better because your body will start to get tired on cue
• Avoid alcohol at night - alcohol consumption may initially help you to fall asleep but you’ll end up having very light and poor-quality sleep
• Consider wearing an eye mask to sleep - especially in the summer months when it gets very light in the mornings, an eye mask can help block out the light. If eye masks aren’t your thing you could also try blackout blinds
• Exercise regularly - this can help you to sleep much better; however, avoid exercise 3 hours before you go to sleep as this can cause problems unwinding
• Avoid eating within 3 hours of going to bed - eating just before bed can make it hard for you to stay asleep as digesting your food takes a lot of energy