Tension Headache: This is the most common type of headache and can cause pain around the eyes due to muscle tension. The intermediate duration of 3 years suggests a chronic condition, which is consistent with tension headaches.

Migraine: Migraines can cause severe eye pain and are often accompanied by headaches. The 3-year duration is plausible for migraines, which can be chronic.
Dry Eye Syndrome: This condition can cause eye pain and is often accompanied by headaches due to the constant irritation. It's a common condition that can persist for years.
Sinusitis: Chronic sinusitis can cause headaches and eye pain due to the inflammation of the sinuses, which are located near the eyes.

Giant Cell Arteritis: This is a serious condition that can cause eye pain and headaches, and if left untreated, can lead to blindness. Although it's less common, it's crucial to rule out due to its potential severity.
Temporal Arteritis: Similar to giant cell arteritis, this condition can cause eye pain and headaches, and requires prompt treatment to prevent serious complications.
Glaucoma: This eye condition can cause severe eye pain and headaches, and if left untreated, can lead to vision loss.

Cluster Headaches: These are rare and cause severe eye pain and headaches, often occurring in clusters or cycles.
Trigeminal Neuralgia: This condition causes sudden, severe facial pain, including eye pain, and is often accompanied by headaches.
Idiopathic Intracranial Hypertension: This rare condition can cause headaches and eye pain due to increased pressure in the brain.