Melatonin production is influenced by light (or lack off) and increases in the evening as it gets darker, signaling to your body that it's time to prepare for sleep, and decreases in the morning when exposed to light, helping you wake up. When the cells in our eyes (retinal cells) are exposed to bluelight they send a signal to our brain that its time to be awake and to stop prodcuing melatonin. So holding a phone, tablet or reading device directly infront of our eyeballs at night time will absolutley send the signal to the brain that hey, it's not sleep time, but actually awake time. And here's what happens to your sleep.
Impact on Sleep Quality
The adverse effects of blue light extend beyond just falling asleep. Here's how it impacts sleep quality throughout the night:
Delayed Sleep Onset: Blue light exposure before bedtime can delay sleep onset by inhibiting melatonin production, shortening overall sleep duration.
Fragmented Sleep: Reduced melatonin levels can lead to lighter sleep and increased wakefulness, causing fragmented sleep.
Reduced REM Sleep: Blue light exposure can decrease REM sleep, crucial for memory consolidation and mood regulation.
Overall Sleep Efficiency: The combination of delayed sleep onset, fragmented sleep, and reduced REM sleep leads to lower sleep efficiency, meaning less restorative sleep.
Reducing Blue Light Effects
While it's challenging to avoid blue light entirely, here are strategies to reduce its impact on sleep:
Limit Screen Time Before Bed: Reduce exposure to screens at least one to two hours before bedtime to allow natural melatonin production.
Use Blue Light Filters: Many devices offer blue light filters or "night modes" that reduce blue light emission but these night modes still emite enough light to deactivate melatonin produciton.
Wear Blue Light Blocking Glasses: These glasses filter out blue light and can be useful if you need to use screens before bed. You are looking for ones at are yellow or at a minium have a yellow tinge.
Create a Sleep-Conducive Environment: Dim the lights in your home as bedtime approaches and use warmer light sources that have less impact on melatonin production such as salt lamps or redlight bulbs. Try to avoid turining on lights throughout the night.
Prioritize Daylight Exposure: Ensure you get plenty of natural light during the day to help regulate your circadian rhythm.