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Blue light from screens can disrupt our body’s natural sleep cycle? That’s True.

Screens are everywhere — from smartphones to laptops to TVs. While technology makes life easier, the blue light from digital devices can take a toll on your eyes and even disrupt your sleep. Let’s break down what blue light is, how it affects rest, and what you can do to protect your eyes and your nights.

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🔵 What Exactly Is Blue Light?

When you see a rainbow, you’re looking at the visible light spectrum — the colors our eyes can detect. Blue light is part of this spectrum and has a shorter wavelength, which means it’s more stimulating to the brain.

• について sun (our main natural source)
• LED bulbs and energy-efficient lighting
• Digital devices like phones, tablets, and computer screens

During the day, blue light is beneficial because it helps boost alertness, focus, and mood. But in the evening, too much exposure can confuse your brain into thinking it’s still daytime.

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🌙 Blue Light and Your Sleep Cycle

Your body runs on a natural rhythm called the circadian rhythm — the internal clock that tells you when to wake and when to rest.

Here’s the issue:

• Blue light suppresses melatonin, the hormone that makes you feel sleepy.
• Too much evening screen time can delay sleep and cause nighttime wake-ups.

• Turn on Night Shift (iOS), Night Mode, or Blue Light Filter on your devices after sunset.
• Avoid screens 1–2 hours before bed (swap them for a book, journaling, or gentle stretches).

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👀 Can Blue Light Damage Your Eyes?

• Research shows blue light from screens is not strong enough to damage your retina.
• Most studies that found harm used unnatural lab conditions (cells in a dish, not real human eyes).
• So far, there’s no evidence connecting everyday screen use to macular degeneration or blindness.

In other words: blue light may disrupt your sleep, but it won’t destroy your eyes.

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👓 Do You Really Need Blue Light Glasses?

• Improve sleep
• Reduce eye strain
• Prevent long-term eye damage

• Sleep: Yes, blocking blue light may help — but you can get the same benefit by reducing screen time before bed.
• Eye disease: No evidence links device blue light to serious conditions.
• Eye strain: Discomfort comes from how we use screens, not the blue light itself.

👉 That said, many people find blue light glasses comfortable for evening use. If they help you wind down, they can be worth it. (See our 厳選ガジェット to find your [ Blue Light Blocking Glasses for Sleep]).

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😵 Digital Eye Strain: The Real Culprit

• Dry or watery eyes
• Blurred vision
• Headaches
• Neck or shoulder tension

Why? Because we blink about 50% less when staring at screens. Less blinking = drier, more tired eyes.

1. Follow the 20-20-20 Rule: Every 20 minutes, look at something 20 feet away for 20 seconds.
2. Use artificial tears if your eyes feel dry.
3. Check your distance: Sit about 25 inches (arm’s length) away and slightly below eye level.
4. Reduce glare: Adjust brightness, dim nearby lights, or add a matte screen filter.
5. Switch to glasses: If you wear contacts, try glasses for long screen sessions — they reduce dryness.

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🌙 The Bottom Line

• Limit screen time before bed
• Use Night Mode on devices
• Try calming aids like chamomile tea, meditation, or a weighted blanket

Because protecting your sleep means protecting your health.

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