Phones at Night: A Disruption to the Brain

By Saki Kuramoto

You switch off the lights in your bedroom, flop onto your bed, and scroll through your socials one last time before bed. You finally decide to shut your phone off and close your eyes…but now you find yourself tossing and turning with eyes wide awake.

Unknown to many, the blue light emitted from our devices affects our brains by disrupting our circadian rhythm, thus hindering sleep quality.

What is Circadian Rhythm?

The circadian rhythm is found in the suprachiasmatic nucleus, in a part of the brain called the hypothalamus. Circadian rhythms encompass all physical, behavioral, and mental changes that follow the 24-hour cycle. The rhythm is typically affected by lightness and darkness in an environment.

What is Blue Light?

Also known as high-energy visible light, blue light is a color that can be seen through human eyes and have a short wavelength producing a high amount of energy. Although blue light is beneficial in daylight as it helps reaction time and boosts attention, it is counterproductive when blue light is absorbed at night.

The Effect of Blue Light on Circadian Rhythms

Blue light from the devices suppresses the release of melatonin, the hormone responsible for drowsiness. Blue light exposure, such as your device at night, tricks our brain into thinking it is daytime by disrupting the circadian rhythm, making sleep restless and harder. Chronic misalignment of circadian rhythms can permanently damage retinal cells, metabolic disorders, mental health disorders, and cardiovascular diseases.

Mitigating the Effects of our Devices

• Use blue light filter screens on devices

• Use a lamp that emits orange or red light instead of blue

• Use night mode or dim the screens of devices

• Try to put down devices at least 3 hours before bed

• Purchase glasses with a yellow-filtered lens

• Set the alarm to remind you to turn off devices 2 to 3 hours before bed

Works Cited:

Cultivating Health. “How Blue Light Affects Your Eyes, Sleep, and Health.” Cultivating-Health (blog), March 8, 2022. https://health.ucdavis.edu/blog/cultivating-health/blue-light-effects-on-your-eyes-sleep-and-health/2022/08.

Harvard Health. “Blue Light Has a Dark Side,” July 7, 2020. https://www.health.harvard.edu/staying-healthy/blue-light-has-a-dark-side.

Newsom, Rob. Blue Light: What It Is and How It Affects Sleep | Sleep Foundation. Sleep Foundation, 2020. https://www.sleepfoundation.org/bedroom-environment/blue-light. WebMD. “Reducing the Effects of Blue Light.” Accessed March 27, 2023. https://www.webmd.com/eye-health/blue-light-reduce-effects.