Different things affect different people differently.
I love f.lux. I have it on all my computers and had it on my JB iPhone 4S. I reluctantly gave it up when switching to iOS 7.
Having said that, I have always tried to avoid using electronic devices / watching TV for an hour before bed - doesn't matter if they have f.ux or not. (I often fail in this goal but the aim is there) .
My sleep patterns get messed up very easily (ADHD) so I value f.lux.
Own your medical needs. Take the action you need. I agree it would be nice if Apple allowed f.lux, or created a similar process, on ios 7, as part of the disabled access section. I think you could build a strong case here, especially if you are reasonable, and get many people on your side.
I'm also deaf, and so are many other people on MR, so access is a big thing for us, and Apple has done quite well here. So you are in with a chance.
Having said that; so.... No f.lux on iOS 7....
Own your needs like I said above. Either stop using your phone an hour before bed, or switch to Android, or buy / craft an orange film cover to put over your display in the evenings. iOS 7 pull-up menu is excellent for quickly dimming in the dark. Better than iOS 6 in this area.
I like the idea of the orange glasses - I might get some myself to help with my own issues. Can't find any on UK Amazon that fit over glasses though
