What Is Blue Light? The Electromagnetic Spectrum

All light, including blue light, is made up of electromagnetic particles that travel through the air to our body in waves. These waves emit energy and depending on the colour, the strength and range of the light can differ. A shorter wavelength is associated with higher energy levels. The unit of measure for light is nanometres (nm) with 1 nanometre equalling just 1 billionth of a meter. Grouped up these items create the electromagnetic spectrum, but only some of these are visible to us.Blue Light & The Electro Magnetic Spectrum. Radio Waves, Microwaves, Infared, Visible Light, Ultraviolet, XRays, Gamma Rays. Wavelengths and Visible Light

Electromagnetic Wavelengths

  • – Gamma Rays
  • – X-Rays
  • – Ultraviolet (UV) Rays
  • – Visible Light
  • – HEV Light (High Energy Visible)
  • – Infrared Light
  • – Radio Waves

 Blue Light & The Eye

Science has proven the human eye is especially sensitive to light inside the ‘visible light’ spectrum. Visible light consists of these colours: violet, indigo, blue, green, yellow, orange and red.The Visible Light Spectrum from 700nm to 400nm, Red, Orange, Yellow, Green, Blue, Indigo & Violet

Blue light has one of the shortest wavelengths and produces a much higher amount of energy. Many studies suggest exposure to the blue light spectrum over time causes severe long-term damage to your eyes and can affect other areas of our brains.

The blue wavelength is excellent during the day as it increases attention, improves reaction times, and lifts mood, but it is the most troublesome wavelength at night. Many of us are surrounded by screens everywhere, from the second we leave for work, school, in the car to the last minutes of awake time before (trying) to go to sleep. Overall it makes blue light very difficult to escape.


Blue Light (High-Energy Visible) and Blue Light Blocking Glasses

The eye’s cornea and lens are unable to filter or deflect Blue Light.

Photochemically-induced retinal injury is caused by the absorption of light by photoreceptors in the retina. Photoreceptors such as rod cells, cone cells & photosensitive ganglion cells convert light into electrical signals in the eye. Normally, when light hits a photoreceptor, the cell bleaches and becomes ineffectual until it has recovered through a metabolic process called Wald’s visual cycle. This visual cycle is the biological process which converts photons, such as electromagnetic radiation (UV light & Blue Light) into electrical signals in the retina.

When the retina is constantly and repetitively subjected to the presence and absorption of Blue Light, at a wavelength 400 – 500 nm, rod cells & cone cells become unbleached and responsive again to light before they are ready.

A few minutes of exposure to Blue Light at 408nm is enough to cause permanent death of photoreceptors and lesions of the retinal pigment epithelium.

Blue Light, Eye & Vision Damage


Now let’s compare wavelengths…

    • Blue Light (HEV) versus Ultra Violet A, B & C
    • UV-C (100 nanometres to 280 nanometres)
    • UV-B (280 nanometres to 315 nanometres)
    • UV-A (315 nanometres to 400 nanometres)
    • Blue Light (400 nanomatres to 500 nanometres)

What does this mean?

At a wave length between 400 – 500 nm, Blue Light passes through the cornea and lens and reaches the retina.


What are some of the known side effects of being exposed to Blue Light?

    • Cataract formation (also caused by long term exposure to UV light)
    • Age-related Macular Degeneration, the leading cause of low vision & complete vision loss
    • Night Blindness (also caused by lack of vitamin A)
    • Computer Vision Syndrome
    • Sleep deprivation / insomnia
    • Depression
    • Immune system suppression
    • Unstable moods / mood swings

Did you know…

    • Children’s eyes absorb more Blue Light than an adults, therefore children are at higher risk of sustaining vision impairment from exposure to Blue Light from digital devices

What are some known devices that emit Blue light?

    • LED lights (even in indirect presence, such as lightbulbs)
    • LED screens / TVs
    • Compact fluorescent lights
    • PC/laptop monitors
    • Smart phones / tablets

What can you do to prevent vision impairment and detrimental health issues contributed by Blue Light exposure?

    • Buy Blue Light Blocking Glasses.