Understanding Ultraviolet Radiation and How to Choose the Right Pair of Sunglasses for Protection

Understanding UV Radiation and Sunglasses for protection

Sunglasses are one of the most popular fashion accessories since they not only enhance your appearance but also protect you from the elements. Long-term exposure to the sun can cause discomfort, headaches/migraines, and a range of other health issues since our eyes are sensitive. In this article, I'll explain what UV radiation is, how it affects our eyes, and how to pick the best pair of sunglasses for complete protection.

Spectrum of Light

The sun's energy reaches the planet in three forms:

  • Visible light with a wavelength of 380 to 780 nm 
  • Heat-producing infrared radiation with a wavelength more than 750 nm
  • UV radiation with wavelength below 380 nm can't be felt or seen, but it can hurt you if you're exposed to too much of it.
    Ultraviolet radiation spectrum of light
    Fig 1: Electromagnetic spectrum of light

    UV Radiation

    There are three forms of UV radiation, and the ozone layer's depletion is increasing the amount of UV radiation on the planet:

    • Ultraviolet A radiation (UVA): When exposed, UVA radiation causes skin aging, eye damage and skin cancer.
    • Ultraviolet B radiation (UVB): Only a small percentage of UVB radiation reaches earth but prolonged exposure can cause skin damage, cancer, and sunburn to cornea of eye.
    • Ultraviolet C radiation (UVC): This radiation doesn’t reach earth so no effect on us.[1]
    UV radiation types from sun to earth
    Fig 2: UV radiation from Sun to Earth

    Not all UV radiation is bad for us, UVB radiation helps skin produce vitamin D3, which, along with calcium, is important for bone and muscle health. However, the amount of UVB exposure, the amount of vitamin D in your diet, your skin color, where you live, and the time of day/year all play a role. Certain UV radiation is also used in medical treatments. [2]

    Problems caused by UV radiation

    Overexposure to UV A/B radiation causes cataracts (opacity of lenses), eye cancer, pterygium (surfer’s eye) and macular degeneration [3], photochemical damage is induced in the eye due to long-term exposure to lower levels of light in UV and blue regions of the spectrum [5]. Strong reflections from sand, water or snow can cause acute effects of UV radiation exposure like, photokeratitis and photo conjunctivitis.[5]

    Cataract and diseases caused due to exposure to Ultraviolet radiation
    Fig 3: Comparison of healthy eye with cataract and pterygium

     

    UV400 Sunglasses

    It is critical to protect your eyes from excessive ultraviolet radiation by wearing sunglasses that provide 100 percent protection from both UVA and UVB rays. FYEWEAR's "UV400" protection means that sunglasses with this level of protection block all radiation in the electromagnetic spectrum of light up to 400 nm wavelength (including both UV A/B rays) [4]. Sunglasses with this level of protection block an even wider spectrum than CE and British Standard models, making them the ultimate eye protection.

    Demo to show FYEWEAR sunglasses have total Ultraviolet (UV) rays protection
    Fig 4: FYEWEAR’s UV400 lens UV protection demonstration. You can see that in Fig 4 (A) the security thread of USD 20 bill is glowing because of the UV light projected on it, however, the security in Fig 4 (B) is not glowing because UV light is filtered out by FYEWEAR’s UV400 shades

     

    Additional Protection

    Here are a few more ways to protect your eyes from UV rays:

    • Wear a cap or hat, as well as sunglasses.
    • Even on a cloudy day, UV rays are there, and UV radiation can travel through clouds and haze.
    • Intensity of sunlight is high from noon to early afternoon, at higher altitudes  and reflection from the water/snow surface raises the intensity even more.
    • Avoid looking straight into the sun, as this might cause retinal damage.
    • Last but not least, protect small children too from UV radiation; cover them with caps/hats and UV400 sunglasses. [4]

      I genuinely hope you would enjoy the outdoors while wearing caps/hats and UV400 sunglasses to protect your eyes.

       

      References

      Ref 1: Ultraviolet (UV) Radiation and Sun Exposure | US EPA

      Ref 2: Ultraviolet (UV) Radiation | FDA

      Ref 3: Ultraviolet (UV) protection | AOA

      Ref 4: The Sun, UV Light and Your Eyes - American Academy of Ophthalmology (aao.org)

      Ref 5: Radiation: Effects of ultraviolet (UV) radiation on the skin, eyes and immune system (who.int)
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