I did wonder that, but I just can't think of anything he has in his cage that is dark brown. I am just so happy that it is back to normal, every time I see perfect coloured urine it puts such a huge smile on my face!!
Luckily he doesn't mind me bathing his eye too much, I just wondered if he should be having any eye drops to stop it from sticking up?! I bathed it this morning and by lunchtime it was half closed again, I just worry it must be annoying or a little uncomfortable for him.