He's been wanting to go to bed for the last hour or so and I caved about 10 minutes ago and popped him in bed, he's been awake since about 3am so must be absolutely knackered. He's blind and has complex disabilities (part of which is disordered sleep) so when he wakes in the wee small hours there is no negotiating with him to get him back to sleep and he doesn't get the same cues non-blind people get when it comes to sleeping.
Who knows what time he will wake. It could be 5am or it could be before midnight (we have tried melatonin, it didn't work).