Wandering around the flat, turning off lights, lowering blinds, turning monitors as dim as I can; turning my own to inverted colors so it’s darker. (Ctrl-Option-Cmd 8, if you have a mac.) It doesn’t actually help, but it’s something I can do.
Cluster headaches: go away. We hate you. You are not welcome here. Leave.
 “The term “headache” does not adequately convey the severity of the condition; the disease may be the most painful condition known to medical science.”