Got Me Feeling Blue

Sleep schedules are an early casualty in the fight to be productive. Getting good sleep is an uphill battle, so anything that can help us is a welcome ally. We all know about the phone and computer settings that turn down the infamous blue hues at sunset, but what about when you want more blue light? Maybe you want to convince your body to stay awake to pre-acclimate for a trip across time zones. Perhaps you work or live in a place that doesn’t have windows. Menopause introduces sleep trouble, and that is a perilously steep hill.

[glowascii] takes the approach of keeping-it-simple when they arrange six blue LEDs under a flesh-tone patch, which isn’t fooling anyone and powers the lights with a USB power pack. Fremen jokes aside, light therapy is pricey compared to parts some of you have sitting in a drawer. Heck, we’d wager that a few of you started calculating the necessary resistor sizes before you read this sentence. Even if you don’t need something like this, maybe you can dedicate an afternoon to someone who does.

DIY therapy has a special place in our (currently organic) hearts, such as in this rehabilition glove or a robot arm.

Thank you for the tip, [cyberlass].

22 thoughts on “Got Me Feeling Blue

      1. We draw yellow because the only time you can look directly at the sun is when it’s low in the sky .

        It’s bright white(of course) and turns yellow then red for the same reasons the sky is blue.

        1. Prove me wrong, but the direct sunlight on earth surface is really a bit yellow(ish), because blue light is partly scattered by the atmosphere. For our eyes the yellowness is also enhanced because of the blue sky/yellow sun contrast. Cloudy sky is the “real” white.

    1. And just last night I was searching for a way to classify the spectral output of LEDs that didn’t cost an arm and a leg. I wanted something that would sense a range between blue and the UV spread, but everything I could find was either bio florescence lab equipment, or sunlight photometers with too narrow a range.

          1. You missed the part I mentioned CCD.

            >Generally speaking, filtered digital sensors are sensitive to a much broader range of light than the human eye, from about 250nm (the near-UV range) through visible light (400nm to 750nm), and down about 780nm (the IR range). Unfiltered, a digital sensor is sensitive to a far greater range, from deep UV (200nm, true UV) down to true IR (as far as 900nm)

          2. Also there are all kinds of UV sensitive materials: dye, blacklight paper etc.
            This is Hack a Day, NOT Instructable. We chat about ideas not a full fool proof project that you can just copy/paste without using your grey matter.

          3. A fluorescent screen can often help “visualize” the UV light that is just above* the human visible window. (And if I recall correctly from way back in college even plain white paper fluoresced a little bit.)

            *Above on the energy/photon basis, i.e. higher frequency but shorter wavelength.

            Camera CCDs, despite their RGB filters, can also detect (rather poorly) outside their design range, but that will still be better more for visualization rather than measurement.

            For actual detailed “measurements” (which it seems you’re after, based on the comments further up in the discussion) you’re going to want a grating, a basic photodetector with a well-documented spectral responsivity and go from there. The trick is to leverage the prism-like color-splitting behavior of the grating so that you know what specific band of wavelengths are entering your detector (based on the geometry of your light-grating-detector setup), and then use the lookup tables for the spectral response to convert whatever amperage you’re reading from your detector into the proper photons/second type unit. You’d ideally have some well-known reference light sources to calibrate your detector set-up before testing unknown samples though (unless you just need a ballpark figure).

            I’m not sure if there is a better/cheaper/easier way to characterize the spectra of a light source, but this sweeping of the detector angles and measuring the output was what we did back in the day for undergrad optics lab.

          4. I’m sorry, my grey matter was busy with the actual project, and not falling down the rabbit hole of designing and building a reliable measurement tool that I had no previous experience with, but which is necessary to accomplish my goal. I’m well aware of the fact that a CCD sensor can detect light beyond the visible spectrum and what a diffraction grating is, but neither of them by themselves will give me a readout in nano-meters. That’s why I was looking for a preexisting tool, or project to accomplish it.
            There is not one single post on Hack-A-Day that is a manifestation of pure original thought, with no reliance on prior work whatsoever. Hence, the name.
            If it were “Original-Patentable-Idea-A-Day” , I doubt there would be much to read.
            You can give a man a fish, or you can teach a man to fish, but giving a man a link to an article that tells him he can take a picture of a fish accomplishes nothing.

            I am looking to classify readily available Blue, Violet and UV LEDs sourced from common devices that give no specifications and that have spectral peaks in specific ranges in order to determine which ones are safe at what which exposures from ionizing effects on materials, and which ones have peaks at or near 405nm (possible sanitizing uses). Now if you had a link to a teardown on a Opsytec UV Radiometer UVPAD, I would find that incredibly useful.

    1. That’s a slight exaggeration, but in general you should not be aiming blue LEDs at your eyes like this. My blue light therapy device says to place it off to the side but it’s also got a big huge diffuser built into it.

  1. Think of all the wasted light missing the pupils. Bring on the eye tracking, variable diameter laser beams. A pair should naturally shoot directly into the user’s eyes, but to share the love, forward facing tracking laser cannons can bring happiness to the user’s friends and passing strangers too.

      1. An idea for the start of the post:

        Blindness is sweeping a small area of Nottingham. Nobody is quite sure why as people aren’t making it back out to report. The question is, when will they stop sending in more people to investigate. Sources close to the action report screams of “THE BLUE LIGHT!! ARRGHH!!” and similar. Often followed by “Ouch!”, or “You’re treading on my foot!” Is it a mass brawl, it is some sort of X-Men thing? We don’t know, but if it is, it would be cool. So off we go.

  2. This whole blue light thing affecting sleep and such is very poorly studied. One unknown is if this blue light matters in relative or absolute terms. I think it’s both, but with a very strong absolute component.

    That would mean that all the stuff we pretend to be a fix (making screens a bit more yellow and making sure to use only warm lights) is pretty useless and pales in comparison to the intensity of the light. Maybe it looks good to have 20% less blue light in your screen, but the brightness perceived by the eye due to your brightness setting and distance will vary over orders of magnitude making that 20% meaningless.

    1. Once the light level gets low enough, your cones go to sleep and it looks colorless anyhow. I have some blue pilot lights in the bedroom and I thought about changing them to red, but ….. zzzzzzZZZZZ

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