Blue and Purple Lights in Treatment
Blue light
Blue light can be good and bad, depending on the time of exposure; basically blue light exposure via the eye during day time hours is positively good, but after dusk it has detrimental effects on our body clock.
Humans have evolved with a reliance on blue light exposure during the dayt ime hours. Blue light via the eyes suppresses melatonin more than any other light wavelength; this means that during the day blue light exposure helps keep us alert, and can help with mood disorders, but this effect is not desirable in the evening and at night time; this is where the light of computer devices and phones etc comes in - it is naturally high in blue light and these appliances should be avoided in the evenings.
Blue light has been widely used in dermatology for decades for the treatment of acne. it can kill the proprionibacteria that contribute to acne, but also reduces redness and inflammation. it has some stimulatory effects of collagen and elastic production in the skin.
But as important as its effect on the skin - blue light has a massive effect on regulation of our body clocks; this effect is brought about by blue light enetering the eyes, and affecting the hypothalamic-pituitary axis, which controls our sleep-wake cycle, and also many of our bodily hormonal rhythms. It is also important in maintaining neural health and may reduce the risk of neurodegenerative diseases.
Purple light
Purple light therapy increases cell repair and regeneration. It decreases the telomeres of DNA in the cell to essentially bring it back to a stem cell-like (brand new cell) state so that it can divide and create new cells. This is important in cells which undergo a lot of turnover, such as the skin.