Do Sunglasses Block Blue Light? Their Effectiveness

Do Sunglasses Help Block Harmful Blue Light?

With the dramatic rise in screen time from computers, phones, tablets and TVs, many people are concerned about exposure to blue light. This visible light wavelength can disrupt sleep and potentially cause eye strain and other health issues over time. Special eyewear like blue light filtering glasses has emerged as a possible solution. But do sunglasses also help protect against blue light?

Understanding Blue Light

Blue light is a high-energy visible light ranging from 400-500 nm wavelengths. It has unique properties compared to other light wavelengths:

• Helps regulate the sleep-wake cycle and hormone production
• Boosts alertness, mood and cognitive performance
• Can damage retina cells and contribute to macular degeneration later in life
• Causes digital eye strain when overexposed due to pixel scatter

A little blue light exposure is healthy. But excessive amounts late into the evenings from electronics disrupt natural sleep rhythms and can lead to fatigue, poor vision, headaches, and long-term threats to eye health.

Do Regular Sunglasses Block Blue Light?

When choosing sunglasses, most people look at properties like UV ray protection, frame style, lens tint and price. But can your regular sunglasses also filter out hazardous blue light from your field of vision?

The answer is maybe. Not all sunglasses are equal when it comes to blocking blue light.

Sunglass Lens Material Matters

Certain lens materials inherently filter more blue light than others, including:

• Polycarbonate: Strong, impact-resistant plastic lenses block 100% UVA/UVB rays and about 10% blue light transmission.
• Trivex: Another type of durable, lightweight plastic lens blocks 100% UVA/UVB rays and 15-20% blue light transmission.
• Glass: Glass lenses dont distort vision or scratch as easily but are heavier and more breakable. They filter out 100% of UV rays and typically 35-40% of blue light.

More advanced specialized treatments on plastic and glass lenses can filter even more blue light, ranging from 15% to over 90% reduction. These include specialized dyes, anti-reflective coatings and mirrors or flash treatments on the lens.

Sunglass Tint Makes a Difference

Along with lens material, the color tint or darkness of sunglass lenses impacts blue light filtering capabilities:

• Lighter tints like yellow, amber and green block only a smaller portion of blue light.
• Medium shades like gray, brown and rose block more of the blue light spectrum.
• Very dark tints like mirrored coating, polarized lenses and gradients filter a higher percentage of blue light.

So darker sunglass lenses in materials like polycarbonate or glass provide higher blue light protection.

Do Sunglasses Reduce Eye Strain and Sleep Issues?

Excess blue light exposure from screens at night is linked to digital eye strain and disruptions in melatonin hormone signaling that makes it harder to fall asleep. Can wearing sunglasses help mitigate these issues?

Studies show that wearing good quality UV blocking sunglasses during the daytime does help reduce associated eye fatigue, blurred vision, headaches and dryness experienced at night after overusing devices.

The moderate filtering of blue light wavelengths sunglasses provide is enough to make a difference in easing eyestrain. But most regular sunglasses dont block enough blue light on their own to significantly improve sleep quality at night.

Better Nighttime Blue Light Reduction Solutions

To better support healthy sleep, experts recommend blocking blue light emission from screens themselves at night with:

• Blue light filtering glasses designed specifically for high blue light blocking.
• Adjusting device settings for night/dark modes with warmer screen lighting.
• Downloading apps that filter blue light like f.lux and Iris.
• Avoiding screens for 1-2 hours before bedtime.

Layering these changes with sunglasses worn earlier in the day provides well-rounded protection against the eye health threats of pervasive blue light.

Do Sunglasses Protect Against Retinal Damage?

The vitamin A rich retinal cells at the back of the eye are crucial for healthy vision. But these photoreceptor cells are vulnerable to oxidative damage from excessive blue light over time. Can sunglasses help shield the retinas?

Reducing Macular Degeneration and Retinal Damage Risk

Unfortunately most regular sunglasses do not block enough high-energy blue light to significantly reduce risk of macular degeneration and other retinal damage when worn alone.

But studies show that in combination with a nutrient-rich diet full of leafy greens, omega-3s and antioxidant supplements like lutein and zeaxanthin, wearing UV blocking sunglasses can support long-term eye health.

Supplementary Lenses for Full Protection

For the highest level blue light blocking to protect the fragile retina, ocuvite lenses that fit over regular lenses filter out up to 90% of high-energy blue light while still allowing enough healthy wavelengths through.

These supplementary lenses are advisable for those at elevated risk for macular issues, like people with diabetes, smokers, post-cataract surgery and the elderly. Just wearing these retinal protective lenses for nighttime device use significantly reduces blue light exposure.

Shopping for Blue Light Blocking Sunglasses

Not all sunglasses adequately filter blue light. When shopping for shades that protect against blue light dangers, look for:

• 100% UV protection markings
• Polycarbonate, Trivex or glass lenses
• Medium to darker tints in colors like brown, gray, green or reddish
• Mirrored, polarized, or specialized anti-reflective treatments
• Close-fitting wraparound styles
• Supplemental clip-on blue light filtering lenses (optional)

A good pair of blue light sunglasses worn daily helps reduce eye fatigue and long-term threats to vision health from excessive digital device use.

While sunglasses alone dont block enough blue light for completely effective nighttime use, combining shades with other blocking solutions provides optimal daily and nighttime eye protection.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment regimen.