VIOLET/blue LIGHT AND ARTIficial LIGHTING
The human retina responds to visible light approximately in the wavelength range 380nm to 700nm. The shorter-wavelengths with corresponding higher-frequencies of visible light pose the greatest hazard to human eye health because they contain greater photon energy. In particular, violet/blue light band, ranging in wavelengths from approximately 380nm to 500nm, has been shown to be the portion of the visible spectrum that produces the most photochemical damage in retinal cells.
In ophthalmology, this high-frequency and high-energy violet light is called High-Energy Visible (HEV) light. Recent research also supports the premise that HEV light may contribute to age related macular degeneration (AMD). Cataracts and macular degeneration have been associated with photochemical damage to the intraocular lens and retina respectively, resulting from blue light exposure. Blue light exposure also has been shown to accelerate proliferation of uveal melanoma cells.
Most artificial light sources such as incandescent, fluorescent, halogen and LED have various degrees of violet/blue light content; particularly LED technology, which has the highest output in the violet/blue regions while lacking in the warmer regions of the visible spectrum. The recent developments and growth in LED technology replacing older less energy efficient lighting technologies, has increased concern about artificial lighting and eye health because of the higher violet/blue light content in LEDs which may cause eye damage over long periods of time, specifically and only where the eyes are in very close proximity to the desk lamp light source. The possibility of long-term eye damage is increased for children and Low Vision people who have very sensitive eyes, Low Vision people mostly place the desk lamp head and reading material very close to their eyes when reading.
The LED lamps referred to in the 'Lighting Solutions' section use technology which reduces the violet/blue light (which is the higher-energy shorter-wavelength range) from the lamp light sources, especially for Correlated Colour Temperatures (CCT) ≥ 5000˚K corresponding to cool bluish white light (5000˚K to 5500˚K appears similar to noon daylight). This technology protects both normal healthy eyes and low vision eyes from glare and potential damage to the retina against sustained close proximity of the eye to the lamp light source.
The benefits are particularly ideal for people who spend long regular hours using close proximity lighting for reading/inspection work or who have low vision conditions such as age related Macular Degeneration which is a degenerative disease of the retina that causes progressive loss of vision in the centre of the eye.