ZEISS BlueGuard

What is blue-violet light?

High Energy Visible Light (HEV; 390-500nm) is part of the visible segment of the light spectrum. Scientific evidence has indicated there are benefits to HEV exposure, however potential associated risks have also been mentioned. (Dualism of blue light).

Blue-violet light

-It is considered to be the potentially harmful part of the HEV spectrum and it is the range between 390 – 440nm of the light spectrum.

-It is everywhere, although its intensity varies greatly. While a typical LCD computer monitor produces a brightness of 250 cd/m2, a clear blue sky at midday is 32 times as bright. Direct sunlight can be thousands of times as bright.

The positive side of blue light

-Blue light around 460 nm influences melatonin secretionto regulate the internal “clock” (Circadian rhythm).

-Blue light (provided during daylight) blocks production of melatonin.

-More blue light: Reducing the secretion of melatonin.Result: Boosts mood and alertness 

-Less blue light: Increasing the secretion of melatonin.Result: Sleepiness(not ideal during the day).

The negative side of Blue Light

Extensive exposure to blue light may be harmful

- Some research has indicated that blue-violet light may lead todamage and deathto the retinal cells*.

Light energy absorption (“heating”) may damage the retinal cells.

Potential damages in the retina may cause toxic reactions.

Macular degeneration can be a severe consequence.

- This photo-induced risk of cell damage is calledbluelight hazard.

What about frequent indoor exposure to light sources with a high proportion of blue light?

We are now exposed to more blue light than ever before due to modern light sources. Smartphones, LED light bulbs, televisions, computer monitors, e-readers and tablets emit high levels of blue light. The emission of large quantities of blue light is one cause of digital eyestrain.

It is important to remember that spending one hour outside on a normal overcast day exposes our eyes to 30 times more blue light than spending one hour inside sitting in front of a screen.

*All images and text belong to Zeiss*