Sleeping With Lights On? Know Why It Can Be Harmful

Sleeping with lights on can have a negative impact on your health and can also lower the quality of your sleep.

Sushmita Sharma
Written by: Sushmita SharmaUpdated at: Dec 23, 2022 00:00 IST
Sleeping With Lights On? Know Why It Can Be Harmful

Light exposure before and during sleep can impact the quality of your sleep in many ways. It can be any form of light from televisions, street lights, or electronic devices. This can leave a negative impact on your health in many ways, including metabolism, obesity, depression, hormonal imbalance and increase the risk of chronic illness. Read this article to learn the impact of lights while asleep on your health.

How Exposure To Light During Sleep Affects Your Body

  • Light plays a significant role in regulating the biological clock of your brain, which is known as the suprachiasmatic nucleus.
    It regulates the circadian rhythm, the body's internal clock that signals alertness and rest. Light exposure in the evening delays your sleep cycle.

  • Light decreases the production of the melatonin hormone in your body, which is responsible for inducing sleep. As a result, it makes it difficult for you to get a good sleep. Melatonin also plays a significant role in controlling blood pressure, reproduction, and preventing inflammation.  Due to the exposure to the light at night melatonin rate decreases, leading to high blood pressure. 
  • You may not be able to get adequate Rapid Eye Movement Sleep even if you manage to sleep with lights on. The next stage of sleep is Non-Rapid Eye Movement Sleep which includes light sleep and deep sleep. There may be interruptions while sleeping, and it reduces time spent in a deeper sleep. You need to spend enough time in each stage of sleep to reap the benefits of good sleep. Your brain needs to spend about 90 minutes at a time in each sleep cycle.
  • Sleeping with the light on can also increase the chances of having insomnia. This is because the quality of your sleep gets affected, and you wake up between your sleep, leading to insomnia. 
  • Your brain faces difficulty in achieving deeper sleep when there is exposure to light during sleep. Your brain oscillations that allow you to go into deeper stages of sleep are negatively affected when you sleep lightly at night. 

Why Is Sleep Important For Your Body

Sleep plays a vital role in maintaining the overall health of your body. It helps repair your brain and body, allows muscle recovery, and supports a healthy immune system. In addition, it helps your body to fight against illness and reduces the risk of chronic diseases. It is also responsible for controlling your mood and maintaining the weight of your body. 

What If I Can't Sleep Without the Lights Off?

If you prefer to sleep with lights on or are afraid of darkness, keep your lights at the lowest settings or use a red-emitting nightlight. A timer-equipped lamp may make it possible to fall asleep in the dark, even if you need light to fall asleep. You can also wear eye masks if you are comfortable using them. It will help in blocking the light during sleep. 

Also Read: What Is Sleep Hygiene and Why It Is Important

Some Healthy Sleep Habits To Follow

  • You can lower the lights in your bedroom before bedtime. It is recommended to lower the lights by 8 pm if you wish to sleep at 10 pm.
  • Adapt a sleep cycle and fix your  wake-up and sleep hours.
  • Avoid drinking coffee or alcohol or taking heavy meals at night.
  • Keep your electronic items off your bed.


Getting good quality sleep is essential to promote a healthy life. If you can't sleep with the lights off, try using a red-emitting nightlight or a time-equipped lamp. Consult your doctor if you face difficulty in sleeping or are sleep deprived.