Thanks for using the forum. I am happy to address your questions, and my answer will be based on the information you provided here. Please make sure you recognize that this forum is for educational purposes only, and it does not substitute for a formal office visit with your doctor.
Without the ability to examine you and obtain a history, I can not tell you what the exact cause of your symptoms is. However I will try to provide you with some useful information.
In general, migraine disorder can cause associated visual and eye symptoms. Typically, a migraine with aura is described as visual symptoms (rather than eye symptoms) such as flashing lights or loss of peripheral vision in one eye followed by a headache. While your eye symptoms are atypical (in the sense that your actual eye is uncomfortable rather than your vision), it is still possible this could be migrainous. Lack of response to one migraine medication does not imply that your headaches are not migraines; sometimes, different medications need to be tried.
By timolol, I assume you mean eye drops. I can not comment on whether or not timolol eye drops would be helpful as this is not really in my area and I do not have experience with this.
It sounds like you have had extensive imaging of your brain. One diagnosis that may not show up on a regular MRI that can cause eye pain and headaches is a dissection: a small tear in the blood vessels that travel up the neck to the brain. This can occur spontaneously in people with certain conditions that affect the blood vessels, after neck trauma, or after chiropractic manipulation of the neck. The pain is often but not always associated with some sort of neurologic deficit as a dissection can often lead to a stroke. In order to exclude this, directed imaging of the blood vessels with an MRA or CTA is sometimes necessary. Again please do not think I am implying I think you have a dissection, you symptoms are again not typical of this either (it does not usually cause the type of eye symptoms you describe), I am just trying to provide you with some possibilities.
If you are older than the age of 55, one potential causes is called giant cell arteritis or temporal arteritis. This is due to an inflammation in the temporal artery and other arteries in the body. Symptoms include vision symptoms one sided headache pain in the temple and jaw that may be triggered by chewing. This condition can be diagnosed by a blood test called an ESR and a biopsy of the artery. It is very important to rule this diagnosis out as it is highly treatable and if left untreated it can lead to vision loss. It is exceedingly rare in people younger than 55, and is more common in even older age groups.
The cause of your eye symptoms may not be neurologic. I recommend continued follow-up with both your opthalmologist and neurologist for your headaches.
Thank you for using the forum I hope you find this information useful good luck.
I am just 32 yrs old. My doctor ruled out temporal arthritis. Thank you v.much for your time and resonse though. It has helped.