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  2. Biological effects of high-energy visible light - Wikipedia

    en.wikipedia.org/wiki/Biological_effects_of_high...

    Blue light, a type of high-energy light, is part of the visible light spectrum. High-energy visible light (HEV light) is short-wave light in the violet/blue band from 400 to 450 nm in the visible spectrum, which in artificial narrowband form has a number of proven negative biological effects, namely on circadian rhythm and retinal health (blue-light hazard), which can lead to age-related ...

  3. Ultraviolet index - Wikipedia

    en.wikipedia.org/wiki/Ultraviolet_index

    Sunburn effect (as measured by the UV index) is the product of the sunlight power spectrum (radiation intensity) and the erythemal action spectrum (skin sensitivity) across the range of UV wavelengths. [9] [10] The UV index is a number linearly related to the intensity of sunburn-producing UV radiation at a given point on the Earth's surface.

  4. Ultraviolet - Wikipedia

    en.wikipedia.org/wiki/Ultraviolet

    Halogen lamps with fused quartz envelopes are used as inexpensive UV light sources in the near UV range, from 400 to 300 nm, in some scientific instruments. Due to its black-body spectrum a filament light bulb is a very inefficient ultraviolet source, emitting only a fraction of a percent of its energy as UV, as explained by the black body ...

  5. Fluorescent lamps and health - Wikipedia

    en.wikipedia.org/wiki/Fluorescent_lamps_and_health

    In 2009, Natural Resources Canada released a report [14] describing the possible UV exposure from several types of lamps. The report states that at 3 cm distance, the recommended daily exposure to ultraviolet radiation for skin and eye damage (if looking directly at the lamp) was attained between 50 minutes and 5 hours depending on the type of ...

  6. Should You Tan When the UV Index Is High? What ... - AOL

    www.aol.com/lifestyle/tan-uv-index-high...

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  7. Visible spectrum - Wikipedia

    en.wikipedia.org/wiki/Visible_spectrum

    The visible range of most animals evolved to match the optical window, which is the range of light that can pass through the atmosphere. The ozone layer absorbs almost all UV light (below 315 nm). [19] However, this only affects cosmic light (e.g. sunlight), not terrestrial light (e.g. Bioluminescence).

  8. Health effects of sunlight exposure - Wikipedia

    en.wikipedia.org/wiki/Health_effects_of_sunlight...

    On the positive side, UV exposure enables the synthesis of vitamin D 3, which is essential for bone health [1] and potentially plays a role in inhibiting certain cancers. [ 2 ] [ 3 ] While vitamin D can also be obtained through dietary supplements, [ 4 ] UV exposure offers benefits such as enhanced subdermal nitric oxide production and improved ...

  9. Electromagnetic spectrum - Wikipedia

    en.wikipedia.org/wiki/Electromagnetic_spectrum

    In frequency (and thus energy), UV rays sit between the violet end of the visible spectrum and the X-ray range. The UV wavelength spectrum ranges from 399 nm to 10 nm and is divided into 3 sections: UVA, UVB, and UVC. UV is the lowest energy range energetic enough to ionize atoms, separating electrons from them, and thus causing chemical reactions.