The dark side of blue light and screen-time

09 Feb 2021

Positive and harmful effects of blue light

Blue or short-wavelength light is crucial for our bodies. During the daytime, blue light activates our body’s internal clock. It boosts our alertness, reaction times and mood.

But blue light is disruptive at night. Nowadays our life is unimaginable without the use of electronics. The rapid increase in screen-time has lead researchers to investigate the consequences of increased exposure to blue light.

Blue light lowers sleep hormone melatonin levels. For instance, it can be twice as powerful in disrupting melatonin secretion compared to the green light. As a result, people experience suppressed sleepiness.

Moreover, blue light at night can disrupt sleep quality. It also delays circadian rhythms and sleep-wake times, contributing to people living out of sync with their internal clock.

What factors amplify the harmful effects of screen-time?

Several environmental factors can contribute to increased harmful effects of screen-time. Holding a device closer to the eyes can be one of the reasons why more blue light is reaching the eye. Interactive use of electronics such as playing a game or social media can also lead to larger sleep disruptions.

A study investigated screen-time and health-related quality of life in adolescents. Interestingly, adolescents using electronic devices in a dark room reported poorer sleep outcomes compared to when using devices in a lit room. One potential explanation for that could be more dilated pupils. This results in more blue light passing through.

Sleep hygiene at night

To adhere to a healthy sleep routine, keep the “bed” associated with sleep and not with daily activities such as working. Dim screens, turn on night modes and switch to warm lighting in your environment in the lead-up to bedtime. Stay out of social media to reduce negative thoughts and information overload.

Ideally, the bedroom should be a screen-free zone. It will help you relax and ensure a good night’s sleep.

See how LYS can help you change your light habits and improve your sleep.