Many devices and other light sources that use light emitting diodes (LEDs) emit lots of light in the blue wavelengths (430 – 500 nm). The retinal ganglion cells in the eye are highly sensitive to blue wavelengths. Do you know what this means for your biology, your health?

Human melanopsin forms a pigment maximally sensitive to blue light ( λ_max ≈ 479 nm) supporting activation of G_q/11 and G_i/o signalling cascades

Melanopsin cells in mammals are specialized for measuring ambient illumination, contributing to visual discrimination [8,9], and driving a wide variety of physiological responses including, but not restricted to: synchronization of circadian clocks to light : dark cycles, regulation of pupil size, modulation of sleep and suppression of pineal melatonin production [10 –14].

Human melanopsin is therefore capable of inducing significant calcium mobilization in HEK293 cells.

In the case of human Opn4, these data were well fit with templates corresponding to λ_max around 479 nm (figure 3c,d).

We find that the human melanopsin action spectrum can be closely fit by the predicted absorbance spectrum of an opsin : vitamin A1 photopigment with a λ_max of 479 nm (figure 3b).

Source: https://royalsocietypublishing.org/doi/10.1098/rspb.2012.2987
Authors: Helena J. Bailes and Robert J. Lucas

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