Search Here

Smartphone screens emit blue light, but new research suggests it might not be the main reason why people have trouble sleeping.

What is Blue Light?

Blue light is a type of light with a short wavelength that can be found in natural sunlight and artificial sources such as LEDs and screens. Exposure to blue light, particularly in the evening, has been thought to suppress melatonin production, the hormone that regulates sleep, making it harder for people to fall asleep. This concern arose from studies that highlighted the impact of blue light from screens on sleep patterns, leading to the widespread belief that using smartphones before bed disrupts sleep.

Is it Really Keeping Us Awake?

Recent studies challenge the idea that blue light from smartphones significantly affects sleep. A comprehensive review published in Sleep Medicine Reviews, and discussed in an interview, analyzed 11 studies from around the world and found no substantial evidence that screen light in the hour before bed makes it more difficult to fall asleep. 

Stuart Peirson, a professor of circadian neuroscience at Oxford University, notes that the intensity of light is crucial; brighter light has a more significant impact on sleep and circadian rhythms. Given that smartphone screens are relatively dim compared to natural sunlight and even LED bulbs, the actual impact of blue light from screens is minimal.

Stressful Content and Doomscrolling

The primary issue may not be the blue light itself but the activities performed on smartphones before bedtime. Engaging with stressful content, such as work emails or social media, can lead to anxiety and negatively affect sleep. Doomscrolling, or consuming negative news, can also result in poorer sleep quality. Additionally, the habit of using phones close to bedtime can lead to delayed sleep due to prolonged engagement with content.

Passive vs. Interactive Use

Another factor is the difference in impact between passive screen use, such as watching TV, and interactive screen use, like playing video games. Interactive use tends to be more stimulating, even though both activities expose users to similar levels of blue light.