My experience is that they make a big difference, but you have to set them to be quite strong in order for them to do so. So much so that for example the built

My experience is that they make a big difference, but you have to set them to be quite strong in order for them to do so. So much so that for example the built in feature on mac/ios isn't strong enough even at the maximum configurable strength! However, 3rd party apps like f.lux on mac or twilight on android can set the redness much stronger at which point it really does make a difference.