thanks for the helpful information! if his condition gets poor we will take him back to the vet.
no picture of his eye because he moves too much, but it's probably 30% more swollen than in the initial photos, although it does seem quite stable now, but there is a bit of reddening around the eye, presumably from irritation! I can see when light shines on his eye that there's what looks like fluid buildup going on inside the eye (vet saw this)
he gets a tablespoon of food every day, plus 2-3 mealworms which I mainly use for encouraging him to take medication.
the baytril has run out as of this morning, it's a shame it didn't help
he is active, but his sleep is definitely a lot more disturbed. he doesn't enjoy going up and down levels like he used to (it's a safe 3 levelled cage, don't worry, it meets requirements and he's never showed signs of wanting a bigger one) he likes to sleep on the top level in the sand bath with some bedding. he usually goes through cycles of waking for 30 minutes and then snoozing for about an hour or so at night, then in the daytime he sleeps lightly.
I've noticed that he's been scratching a bit, I'm not sure if I'm just examining him more, but he's targeting his upper legs & belly & the top of his head. no signs of mites or anything and no fur loss in these areas, so I'm assuming he's doing it because he's uncomfortable :/
he still wants to run around and enjoys playtime for about 30 minutes twice a week, as opposed to half an hour a day when he was younger/middle age.
thanks again, I'll consider his other behaviour besides eating from now on.