LEDs, and especially those that produce white light, are great for lighting applications. They consume little power in comparison to incandescent lightbulbs and it is easy to create nice colour effects with them. To produce white light a white LED often generates blue light and filters it with yellow or orange phosphor. The problem is, however, that blue-light wavelengths appear to have important health effects such as disruption of the circadian rhythm, accelerated eye aging, and eye strain.
LEDs, and especially those that produce white light, are great for lighting applications. They consume little power in comparison to incandescent lightbulbs and it is easy to create nice colour effects with them. To produce white light a white LED often generates blue light and filters it with yellow or orange phosphor. Unfortunately, blue-light wavelengths appear to have important health effects such as disruption of the circadian rhythm, accelerated eye aging, and eye strain.
White LED light contains potentially harmfull blue light.
Two addtional blue light filters
The AS7264N tri-stimulus colour sensor by ams can measure blue-light wavelengths accurately, and is therefore suitable for human-centric lighting. The sensor’s on-wafer silicon interference filters create spectral channels that match the CIE 1931 XYZ standard observer model while two additional filters allow accurate measurements of blue light intensities at the 440 nm and 490 nm wavelengths.
The AS7264N provides easy-to-use digital colour measurement outputs over an I2C interface. Programmable on-chip LED drivers enable direct control of synchronized electronic shutter functionality. The sensor’s small size (4.5 mm x 4.7 mm x 2.5 mm) makes it easy to integrate it in luminaries, allowing real-time monitoring of blue light exposure of end users.
Address the interaction between light and human health
With its measurements of photobiologically active wavelengths, the sensor serves applications that address the interaction between light and human health. Ambient light characterization and light exposure data collection for commercial, residential, and industrial lighting are applications that come to mind.
Controlling the emission of blue light wavelengths at the source seems a much better solution than wearing special blue light filtering glasses or sticking yellow films on displays. White LED light may be superior for illumination in terms of colour rendering, preserving your eyes is important too. Therefore replacing all the lightbulbs in your home by LEDs is not a good idea.
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Discussion (1 comment)
Graham Warner 7 years ago
True that higher-energy blue wavelengths can result in oxidative damage to certain occular tissues, the most likely scenario is that an image formed from light composed of a few dominant wavelenghts (colours) widely spread across the visible spectrum will be significantly de-focussed. This is because the refractive index of every material is not constant but is a function of the wavelength under consideration. Thus the blue component of the image will be focussed in front of the retina, the red/yellow/orange component on the retina, and the 'distance' between these image components could be as much as 0.5 dioptres. When the spectral distribution of the light source is 'smooth' as in incandescent or daylight, this effect will be rather less problematical than when the energy is concentrated into sharply-demarcated and widely separated bands as from an LED source. Thus, while possibly causing temporary discomfort ("eyestrain") in relation to visually-demanding tasks, LED lighting could not be claimed to 'damage' one's eyes in this way.