Blue Light – Good or Bad?

There are many articles on the internet saying that blue light is bad for you. Depending on the article’s title, it’s easy to see they are talking about the blue light in your technology. Such as scrolling through your cell phone or tablet before bed.  However, sentences like this, “It’s no secret that blue light harms our vision by damaging the eye’s retina.” ( has people asking smart questions about therapeutic blue light, and if it’s the same light found in the screens of our technology.

So what is therapeutic and non-therapeutic blue light?

Therapeutic blue light would include the sun, at specific wavelengths. It would also include SAD devises and laser/LEDs at specific wavelengths & power outputs.

Non-therapeutic blue light would include the sun, with all it’s colors/wavelengths, digital screens/electronic devises, and indoor lighting such as fluorescent & incandescent light bulbs.

The sun & common light bulbs emit light in all spectrum of visible light – hence the name “full spectrum light”.  The image below shows the spectrum of visible light to the human eye.

An incandescent light bulb is an electric light with a wire filament heated to such a high temperature that it glows with visible light (incandescence). The filament is protected from oxidation with a glass or fused quartz bulb that is filled with inert gas or a vacuum.

Florescent light is when an electric current in the gas excites mercury vapor, which produces short-wave ultraviolet light, that then causes a phosphor coating on the inside of the lamp to glow.

Therapeutic blue light uses the natural power and qualities of the sunlight, which science now knows is a wavelength between around 400nm and 500nm. It’s only using the beneficial aspects of the visible spectrum of light in the blue wavelengths.

Therapeutic blue light has been demonstrated to be effective in killing or inhibiting the growth of fungus, yeast, anti-biotic resistant bacteria, and the herpes virus. It’s been found to be calming to the nervous system, antimicrobial, extremely antibacterial, energizing to the brain, and mood elevating. 

So yes, there is bad blue light, but there is also beneficial modulated blue light. Perhaps one day soon we can be using more of the beneficial therapeutic light to illuminate our homes and offices.

If you found this blog interesting check out Photonic Therapy Institute for upcoming “Intro to Equine Light Therapy” classes and our free weekly Office Hours webinars where we welcome anyone who would like to learn more about Light Therapy & Photopuncture.

Owner of Connolly Photopuncture, Certified Human and Equine Light Therapy Instructor, Certified Pet Light Therapist, Secretary for the Board of Advanced Natural Health Sciences