Is Blue Light Good or Bad?

The short answer is that it depends on the timing, intensity, and wavelength.

Blue light is a type of High Energy Visible light that falls within the 400 to 500 nanometer range of the visible spectrum.

Shorter wavelengths, particularly those closer to the ultraviolet range around 400 to 450nm, carry more energy. Some laboratory and experimental studies have examined whether prolonged exposure to high intensity blue light in this range may affect retinal cells. Research into long term effects is ongoing.

At the same time, blue light also plays an important role in overall health. Exposure to blue light during the daytime helps support alertness, mood, cognitive performance, and regulation of the body’s natural sleep wake cycle.

The key factor is balance.

During the day, exposure to natural blue light supports normal circadian function. In the evening, high levels of blue enriched artificial light may interfere with the body’s natural wind down process.

Focus (Previously Day) Swannies are designed to reduce a portion of higher energy blue light in the 400 to 450nm range while still allowing some blue light to pass through for daytime function. Sleep Swannies are designed to reduce a larger portion of blue light in the evening when light sensitivity to circadian timing is greater.

Managing when and how much blue light you are exposed to is often more important than eliminating it entirely.