I'm aware that as little as 200 lumens of light is enough to disrupt sleep in sensitive individuals. Blue light in 460-480nm wavelength is especially powerful for disrupting sleep via reducing melatonin secretion.

This brings me to the question - I have a number of tech gadgets which use LED lights, especially blue LED lights. These give off quite a lot of light, especially noticeable late at night.

How can I dim the LED lights in my room or change their wavelength to something less disturbing?

I tried putting semi transparent tape over them with limited success - maybe there's already something available to solve the problem?

  • 3
    A "sleep mask" that covers your eyes would solve your issue as well. Commented Nov 9, 2015 at 18:01
  • @BrettFromLA For me it's enough just to close the eyes. So I can sleep even during daylight, unless the sun is shining into my face directly.
    – ott--
    Commented May 15, 2016 at 13:27
  • @ott - That's what you think. Research states that you are not getting the quality of sleep you need. You need different levels of sleep which you cannot attain due to the light you receive through your closed eyelids that you are not consciously aware.
    – Stan
    Commented May 15, 2016 at 15:17
  • Did you try turning off your gadgets? Save power, get sleep. Win-win.
    – Floris
    Commented Feb 8, 2017 at 19:53
  • +1 for sleep mask. Using one every night changed my life. It has the advantage of being usable everywhere you go, as well.
    – user428517
    Commented Apr 24, 2018 at 16:09

8 Answers 8


Two immediate thoughts comes to mind: 1) Move the equipment out of the room, 2) Improve on your dimming idea. Assuming it's not an option to move the equipment out of the room, I'll suggest some other options to dim the lights.

  • Use thicker not so semi-transparent tape – Depending on whether you at any time need to see the lights or not, you could opt for black electrical tape, or multiple layer of semi-transparent tape, or a colored tape which would limit the transmitted light
  • Turn the equipment around – Direct light is worse than indirect light, so if it is an option to turn the equipment around somehow, so that you don't face the lights directly, that would be better
  • Use hot glue on top of the lights – Hot glue is a dark variant off semi-transparent, and if done properly it will just be a little extra bulb on top of the other light. Especially for some LED diodes this could be a viable solution. Do however take into consideration, that this might violate your warranty, and is somewhat more permanent than using tape
  • Use an automated timer to shut off equipment at night – Most likely you are not going to use most of the equipment at night, so don't rule out shutting them down during the night time. This can be done using an automatic timer (or a remote control timer), or possilby a master-slave power outlet.
  • That last option is especially good. You're a smart guy, @holroy! Commented Nov 9, 2015 at 18:00
  • WARNING: Transformers will drain the batteries of devices that remain plugged in if there is no electricity actually flowing. Be sure to unplug any devices from the charger if the charger is not plugged in to the AC outlet and receiving power.
    – Stan
    Commented May 15, 2016 at 3:39
  • I ended up using green masking tape over LEDs - they are still visible, but are 90% dimmer
    – Alex Stone
    Commented May 19, 2016 at 1:06


Get a roll of Black Plastic Electrical tape and cut squares to cover the indicator lights.


Try using a "static cling" Automotive window film. It leaves no residue, and comes in varying translucency. I've got one over the various lights on my laptop for that reason.


I have a lot of annoying blue leds in my room too. I've covered most of mine with black electrical tape -- its very opaque and doesn't let any light through. For the LEDs that I still like to see sometimes during the day, I'll poke a small hole in the electrical tape, sort of to the side of the focus of the LED (where the led is less bright) so I can still check the status of the device without having the oppressive brightness at night. If you want to just dim the led, you can actually stretch the electrical tape very thin. It'll start letting light through at a certain point. Just pull it apart like taffy, cut it to the desired size, and stick it on. You could probably use white electrical tape as well, which would let a little more light through.

For mobile devices that I don't want to have decked out with tape, I charge them under my bed at night. It's simple, but it works to keep the LEDs out of view (especially if your bed has a bed skirt)


Rather than just tape, tape a small square of aluminium foil over each light. You can poke a tiny hole in it, but you might find you don't actually need any of those lights and they're just for show.


I use electrical tape on the ones I don't need to reference during the day. For those I may need to look at, I cover with a strip from an old black t-shirt during the night, and move it if I need to look.


Instead of tape that is mentionned in several answers, you can also use a black marker pen. Compared to tape, the advantage is that it leaves no apparent traces of "life hack" on your devices. Applying the pen multiple times also allows you to tune the level of light as you wish.


If you can, move the gadgets to another room. Not only will this mean the little blue and green lights to indicate they are charging or whatnot won't bother you, but it also means whatever buzzes and vibrations they may emit (as notifications or just a background noise) won't disrupt your sleep. There is no need for your phone to charge right next to your bed - it could charge in the kitchen or bathroom.

If you can't, consider getting a sleep mask - a fabric eyeshade held on with mild elastic. Some people claim these make their faces hot but I have several that are extremely comfortable. They block the light, so you don't need to make the room light-free. As a pleasant side effect, once you come to associate the mask with sleeping, you will fall asleep more quickly even in situations where it's hard to sleep, such as while traveling.

If you can't move the devices or shade your eyes, perhaps something as simple as a small cardboard box that you put (upside down) over the gadgets to cover their lights, and remove in the morning. I wouldn't like this because the box would be around all day, but it could work.

  • 1
    Transformers, those black bricks attached to the plug-end of the thing's power cord, get hot. Putting them in a box won't give them the air circulation they need to keep cool. They can and do melt from the heat. If they melt they can become a fire hazard. Really! ! ! Give 'em plenty of air.
    – Stan
    Commented May 15, 2016 at 15:13
  • So a large box, open at the back, maybe with some holes in it on the sides where there aren't lights, would be safer. Commented May 15, 2016 at 15:14
  • I have a strong, quiet fan salvaged from a computer power supply that is on always cooling my little brickyard. So far, so good.
    – Stan
    Commented May 15, 2016 at 15:22

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