Blue Light: What It Is and How It Affects Sleep

In today’s digitally-driven world, it is almost impossible to avoid blue light. We are exposed to it through our phones and laptops, and with most people using these devices for extended periods for either work or pleasure, it has become an issue that has influenced itself through our sleep patterns. So, let’s take a look at what blue light is and how it impacts our sleep, as understanding these factors and how it affects us is crucial for maintaining healthy sleep habits.

What Is Blue Light?

Blue light is a high-energy, short-wavelength light that appears on the visible light spectrum. Blue light is something that is naturally emitted by the sun and plays a critical role in regulating our circadian rhythm, or the sleep-wake cycle. In addition to sunlight, artificial sources of blue light include electronic devices like smartphones, tablets, and computer screens, as well as energy-efficient LED lighting.

The Effects of Blue Light on Sleep

Blue light exposure, particularly in the evening, can significantly impact our sleep. This is because blue light exposure suppresses the production of melatonin in our bodies, which is a hormone that helps regulate sleep. Blue-light exposure disrupts the natural sleep-wake cycle and leads to several sleep-related issues.

• Delayed Sleep Onset – Blue light exposure in the evening can delay the onset of sleep. When we expose ourselves to blue light-emitting devices before bed, the brain receives signals that it’s still daytime. This makes it challenging to fall asleep when desired, resulting in a delay in sleep onset.

• Reduced Deep Sleep – Deep sleep, also known as slow-wave sleep, is crucial for physical restoration and the consolidation of memories. However, exposure to blue light before sleep decreases the amount of deep sleep experienced during the night. This can leave us feeling less refreshed and rejuvenated upon waking.

• Fragmented Sleep – Even brief exposure to blue light during sleep can trigger awakenings or shallow sleep stages, causing us to experience fragmented sleep patterns or disturbed sleep, making us wake up feeling unrested and fatigued.

• Decreased REM Sleep – Rapid Eye Movement (REM) sleep is associated with dreaming, memory consolidation, and emotional regulation. Blue light exposure before bed has been linked to a reduction in REM sleep duration and overall quality. Disruptions to REM sleep can affect cognitive function, mood regulation, and overall mental well-being.

Moreover, the cumulative effect of delayed sleep onset, reduced deep sleep, fragmented sleep, and decreased REM sleep leads to an overall decline in sleep quality. Poor sleep quality can result in daytime sleepiness, difficulty concentrating and memory, mood disturbances, and a decreased overall sense of well-being.

Strategies to Minimise Blue Light Exposure

Luckily, there are many effective strategies to reduce blue light exposure and thereby mitigate its impact on sleep.

• Blue light-blocking glasses and screen filters can help filter out harmful blue light wavelengths.

• Adjusting device settings to activate "night mode" or using specialised apps to reduce the amount of blue light emitted by electronic screens.

• Limiting device use at least 2 hours before bedtime

• Creating a blue light-free bedroom environment, using blackout curtains, and avoiding bright LED lighting.

Promote Healthy Sleep Habits

In addition to managing blue light exposure, healthy sleep habits are crucial for optimal rest. Establishing a consistent sleep schedule and bedtime routine sends signals to the body that it’s time for bed. Creating a sleep-friendly bedroom environment, including investing in a high-quality mattress from reputable mattress manufacturers, can also contribute to better sleep, as a comfortable and supportive mattress can make a significant difference in your sleep quality.