Does exposure to blue light before bedtime contribute to insomnia?

From the Guidelines

Exposure to blue light before bedtime can contribute to insomnia, and avoiding it is crucial for improving sleep quality. Blue light from electronic devices like smartphones, tablets, computers, and TVs suppresses the production of melatonin, the hormone responsible for regulating sleep 1. To minimize the effects of blue light on sleep, consider the following strategies:

• Avoid using electronic devices at least 1-2 hours before bedtime
• Wear blue light blocking glasses, which have been shown to reduce evening melatonin suppression and improve sleep quality in some studies 1
• Enable night mode/blue light filters on devices, although the benefits of this approach may be limited if illuminance is not also decreased 1
• Replace bright white lights with warmer, dimmer lighting in the bedroom to create a sleep-conducive environment The science behind this recommendation relates to how blue light wavelengths affect our circadian rhythm, tricking the brain into thinking it's still daytime and making it harder to fall asleep 1. By avoiding blue light exposure before bedtime, individuals can potentially improve their sleep quality and reduce the risk of insomnia. It's essential to note that while some studies suggest that blue light blocking glasses and night mode/blue light filters may have benefits, the evidence is not yet conclusive, and more research is needed to fully understand their effects 1, 2.

From the Research

Blue Light Exposure and Insomnia

• Exposure to blue light before bedtime has been shown to potentially contribute to insomnia, as it can disturb the sleep-wake and circadian cycles 3.
• A systematic review and meta-analysis found that interventions to reduce short-wavelength light exposure before bedtime, such as wearing color-tinted lenses, may improve sleep efficiency and total sleep time, particularly in individuals with insomnia 3.
• However, the evidence is mixed, and more research is needed to fully understand the effects of blue light exposure on sleep and insomnia.

Cognitive Behavioral Therapy for Insomnia

• Cognitive Behavioral Therapy for Insomnia (CBT-I) is a effective treatment for adults with chronic insomnia, with clinically meaningful effect sizes 4.
• CBT-I is now commonly recommended as the first-line treatment for chronic insomnia, and its widespread dissemination is necessary to address the public health impact of insomnia 5, 6.
• CBT-I targets the perpetuating factors that contribute to the development of chronic insomnia, and its core components include Sleep Restriction Therapy, Stimulus Control Therapy, Sleep Hygiene, and Cognitive Therapy 5.

Relationship Between Blue Light Exposure and CBT-I

• While there is evidence that blue light exposure can contribute to insomnia, there is no direct research on the relationship between blue light exposure and the effectiveness of CBT-I.
• However, reducing blue light exposure before bedtime may be a useful adjunct to CBT-I, as it can help improve sleep quality and reduce the symptoms of insomnia 3.