How Blue Light Affects Sleep
Question
What Is Blue Light?
Blue light is a high-energy visible (HEV) wavelength of light that’s naturally emitted by the sun and artificially by devices like phones, computers, TVs, and LED lighting. While exposure during the day helps you feel alert, too much blue light at night disrupts your body’s natural sleep cycle.
The Science:
Blue Light and Melatonin
Your body’s internal clock — called the circadian rhythm — is controlled by light. When the sun sets, your brain produces melatonin, the sleep hormone, signaling it’s time to wind down. But exposure to artificial blue light (especially after dark) suppresses melatonin, making it harder to fall asleep, stay asleep, and feel rested.
Common Symptoms of Blue Light Overexposure
Trouble falling or staying asleep
Blue light interferes with your body’s ability to produce melatonin, the hormone responsible for helping you fall asleep. When you’re exposed to screens or artificial lighting late in the evening, your brain interprets that light as daytime and delays melatonin release. This makes it harder to fall asleep at night, and often leads to tossing, turning, and interrupted sleep cycles.
Waking up feeling groggy or unrefreshed
Even if you manage to get the recommended 7–8 hours of sleep, excessive blue light exposure can prevent your body from entering the deeper, more restorative stages of sleep. Without enough deep sleep and REM sleep, you wake up feeling just as tired as when you went to bed — groggy, sluggish, and mentally foggy.
Difficulty shutting down your mind at night
If your mind feels wired, anxious, or overly alert when it’s time to sleep, blue light may be a contributing factor. This “alert state” is a result of your brain being tricked into thinking it’s still daytime. The overstimulation from screens, combined with delayed melatonin production, keeps your brain active when it should be winding down.
Eye strain, headaches, or dry eyes before bed
Prolonged exposure to artificial blue light from screens and LED lighting causes your eyes to work harder. This leads to common symptoms like blurry vision, dry eyes, and tension headaches — especially in the evening when your eyes are naturally trying to relax. This digital eye strain can make it harder to fall asleep comfortably.
Feeling “wired but tired” after late screen use
Have you ever felt physically exhausted but mentally wide awake after scrolling your phone or watching TV late at night? This is a classic sign of circadian rhythm disruption. Your body is tired and ready for rest, but blue light has delayed your brain’s sleep signals, leaving you feeling out of sync — and more likely to stay up even later.
Increased sensitivity to light in the evening
Blue light overexposure can make your eyes more sensitive to artificial lighting at night. You may notice discomfort when switching between bright screens and darker rooms, or even find yourself squinting or avoiding screen use altogether. This sensitivity can be a sign that your visual system is overstimulated and needs recovery time.
The Science:
How Sleep ZM Helps Protect Your Sleep
Our blue light blocking glasses are specially designed to filter the most disruptive wavelengths — particularly the 480–520nm range. With lens options for daytime, evening, and photo-adaptive all-in-one use, you can maintain natural melatonin production and enjoy deeper, more restorative sleep.
SLEEP ZM
Ready to Sleep Better?
Explore our Sleep ZM lens guide or shop our full collection of blue light glasses to find the style that fits your eyes and your life.
