Do you ever struggle to fall asleep and can’t figure out why?

Or perhaps you wake up in the middle of the night for what seems to be no apparent reason? It’s likely that blue light from your phone, TV or tablet is disrupting your circadian rhythm, (i.e. the part of the brain telling you when you should be sleeping or awake.)

Many of us reach for a computer or smartphone after getting into bed. In fact, the 2011 National Sleep Foundation’s Sleep in America poll found that 90% of Americans report using an electronic device in their bedroom within an hour of trying to fall asleep.

Unfortunately, screens on these devices can emit blue light that interferes with our natural sleep cycles. Decreasing exposure to light in the evening, and blue light, in particular, is an important way to help your body naturally prepare for sleep.

How Does Blue Light Affect Sleep?

Circadian rhythms are finely-tuned, 24-hour cycles that help our bodies know when to carry out essential functions. Light is the most important factor in aligning circadian rhythms and, for much of human history, these rhythms were closely aligned with sunrise and sunset.

With the advent of artificial light and electronics, people are being exposed to increasing amounts of light before bedtime. While all types of visible light can affect circadian rhythms, blue light has the largest impact.

We get the most of our exposure to blue light from the sun. Blue light stimulates parts of the brain that make us feel alert, elevating our body temperature and heart rate. 

Blue light suppresses the body’s release of melatonin, a hormone that makes us feel drowsy. While this may be helpful during the day, it becomes unhelpful at night when we’re trying to sleep. Being exposed to blue light in the evening can trick our brain into thinking it’s still daytime, disrupting circadian rhythms and leaving us feeling alert instead of tired.

Chronic misalignment of circadian rhythms can also lead to many negative health impacts, including metabolic disorders and mental health conditions such as depression.

With the significant health consequences associated with exposure to blue light after dark, it’s important to understand the sources of blue light and ways to reduce the risks.

What Devices Give Off Blue Light?

Many people work under artificial lights and are constantly interacting with the screens of electronic devices. It’s understandable to want to know which of these sources emit blue light.

Common sources of blue light include:

  • Fluorescent lights
  • LED lights
  • Smartphones
  • Televisions
  • Computer screens
  • Tablets
  • E-readers
  • Video game consoles
how blue light affects your sleep image

Mitigating the Effects of Blue Light

The most effective way to reduce exposure to blue light in the evening is to simply turn off the sources. This means dimming or reducing LED and fluorescent lighting and turning off electronic devices after it gets dark outside.

Specialty glasses may also be helpful in reducing exposure to blue light. While they may not work for everyone, blue-light-blocking or amber glasses can reduce the melatonin-suppressing effects of bright light. At Eyelation we recommend BluTech lenses . BluTech Lenses can be worn throughout the day to help relieve digital eyestrain, but clinical tests have shown that by wearing them at least three hours before bed, you can shield your eyes from the high energy, short-wavelength light (blue light) that alters your sleep/wake behaviour. Ultimately, BluTech Lenses can increase your melatonin levels, resulting in a good night’s rest, improved sleep, health and productivity.

Since many people can’t simply turn off sources of blue light after it gets dark, here are a few other ideas to reduce blue light exposure that may be interfering with your sleep.

  • Make it a routine: Set an alarm that reminds you to turn off electronics 2 to 3 hours before bedtime.
  • Find a better lamp: If you like to read in bed, try getting a lamp that doesn’t emit blue light. Red or orange lamps work well, as does natural lighting like candles.
  • Learn to dim: Find out if you can dim the brightness on your electronic devices or if they have a “night mode” that reduces the emission of blue light.


Content & Image Sources: BlueTech Lens & The Canadian Association of Optometrists