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.
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
- 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.