My eye is almost OK now (although painkillers are in system), but I did have a slightly bunged up nose when I eventually got up this morning (but not at 6am). When I've had sinusitis before I get face ache/cheek pain, which is horrible, but this was different to anything I've had before.
Pressure on the optic nerve can cause such pain to arise.
Did you go to an opticians recently to get your eyes tested or was it somewhere like a Boots or Specsavers type of place?. If it was the latter I would make an appt to see an optician asap. Do get it properly checked out, your sight is too important!.
It sounds like you do not wear contact lenses, your vision is back to normal and pain gone and you had a thorough eye exam with field and eye pressure checks very recently.
Hmm - a corneal abrasion (perhaps wiping unclosed eye on pillow) or severe corneal drying (from a poorly closed eye lid) can cause severe pain (similar to tooth ache) until it sorts itself out. Alcohol can cause poor lid closure (sleeping with eyes half open) in some people (actually some have poor lid closure even without alcohol). Have you had an eye injury - such as a finger poke or scratch from a twig recently?
The best thing would be to get your optometrist to check you over (can they fit you in today perhaps?), as they will have the knowledge and equipment to quickly rule out the main causes of acute pain - and certainly if any pain or blur remain or return.