- Blue light is known to suppress melatonin secretion at night, which can affect your ability to fall asleep and the overall quality of your sleep.
- TrueDark offers two main types of glasses: "Day Walker" (for daytime use) and "Twilight" (for nighttime use), which should be used according to your needs.
- Using them in combination with software that reduces monitor color temperature (like f.lux) can provide a synergistic effect.
- Caution is required when driving or performing tasks that require color identification. If you have any eye abnormalities or underlying conditions, please consult a specialist.
Does Blue Light Really Disrupt Sleep? A Brief Introduction
Our lives are surrounded by smartphones, computers, and LED lighting, making us prone to blue light exposure even at night. Blue light is a part of natural light and helps regulate wakefulness and our biological clock during the day. However, multiple studies suggest that continuous exposure at night suppresses melatonin secretion, affecting how quickly we fall asleep and the quality of our sleep. Sleep research from institutions like Harvard University has also reported that strong light at night affects sleep hormones.
What is TrueDark? The Difference Between Day Walker and Twilight
Product Overview
TrueDark is a brand of sunglasses featuring lenses designed to block blue light, primarily offering two types: Day Walker (for daytime) and Twilight (for nighttime). Day Walker is designed to block blue light while relatively maintaining natural colors during work, whereas Twilight focuses on sleep induction by strongly blocking not only blue light but also purple and green light.
Our Experience (Day Walker)
When our team tried using the Day Walker for a day, the heaviness in our eyes and mild headaches we usually feel in the evening were alleviated, and we were able to finish long hours of computer work feeling relatively refreshed. It seems especially effective for those who feel discomfort behind their eyes or tend to have dry eyes. However, taking them on and off frequently can actually cause fatigue due to the sudden changes in light, so we recommend wearing them continuously while working.
Mechanism of Action and Scientific Perspective
Blue light is a short-wavelength visible light that adjusts the biological clock (circadian rhythm) in the brain via light-sensitive cells in the retina. Exposure to strong blue light at night can suppress melatonin secretion and delay the onset of sleep. Because of this effect, blue light blocking products are expected to serve as sleep aids. However, they do not necessarily have a "dramatic effect on everyone," as individual differences and lifestyle habits play a significant role.
Additionally, while claims by manufacturers such as "reducing brain inflammation" are interesting, solid evidence in the human body is still limited. For now, it is realistic to consider blue light blocking as one of the methods to improve your sleep environment.
Tips for Use and Precautions
Timing and Combined Use
The Day Walker is suitable for desk work from daytime to evening, while for bedtime preparation after evening, it is common to wear the Twilight 30 minutes before going to sleep. Using them alongside f.lux or your OS's standard night mode on your monitor will shift the screen's color temperature warmer, creating a synergistic effect.
Precautions
- Avoid using them or exercise caution during tasks that require color identification (such as design, photo editing, or color matching) and when driving at night.
- If you experience subjective symptoms like eye pain or decreased vision, please consult an ophthalmologist first. Blue light blocking is not a medical treatment.
- If you need a specific fit or prescription lenses, be sure to check before purchasing.
Conclusion
Blue light blocking sunglasses are a useful self-care tool for those who use screens late into the night or feel eye fatigue in the evening. The Day Walker we tried helped reduce eye heaviness and mild headaches during long hours of PC work, but since it is not a cure-all, we recommend combining it with reviewing your monitor settings and improving your daily rhythm. Strong light-blocking types like Twilight are effective for creating a pre-sleep environment, but please consider that they affect color identification and visibility when going outside. It is best to start with short periods and find a way to use them that fits your lifestyle pattern.
Disclaimer: The information in this article is for general informational purposes only and does not constitute medical advice. Please consult a qualified healthcare professional before making any health-related decisions.