Idiopathic Intracranial Hypertension (IIH): This condition is characterized by increased intracranial pressure without a detectable cause, often presenting with headache, visual disturbances (including blurring of vision and papilledema), and can be associated with fever. The medial deviation of eyes could be indicative of a cranial nerve VI palsy, which can occur due to increased intracranial pressure.

Meningitis: Given the fever, headache, and potential for cranial nerve involvement (suggested by medial deviation of eyes), meningitis is a plausible diagnosis. Meningitis can cause increased intracranial pressure, leading to papilledema and visual disturbances.
Encephalitis: This condition, characterized by inflammation of the brain, can present with fever, headache, and visual disturbances. It may also cause cranial nerve palsies, leading to abnormalities in eye movement.
Brain Abscess: A brain abscess can cause increased intracranial pressure, leading to symptoms such as headache, fever, and visual disturbances, including papilledema. The location of the abscess could influence the type of cranial nerve palsy, potentially causing medial deviation of the eyes.

Subarachnoid Hemorrhage: Although less likely given the gradual onset of symptoms, a subarachnoid hemorrhage can present with sudden headache, fever (due to blood in the subarachnoid space), and visual disturbances. It's crucial to consider this diagnosis due to its high morbidity and mortality.
Cavernous Sinus Thrombosis: This condition can cause cranial nerve palsies (including those affecting eye movement), increased intracranial pressure, and visual disturbances. It's a medical emergency that requires prompt diagnosis and treatment.

Neurosyphilis: In its tertiary stage, neurosyphilis can cause a wide range of neurological symptoms, including cranial nerve palsies, increased intracranial pressure, and visual disturbances. Although rare, it's an important consideration in patients with unexplained neurological symptoms.
Tuberculous Meningitis: This condition can present with chronic headache, fever, and visual disturbances, including papilledema. It's more common in areas with high tuberculosis prevalence and in immunocompromised individuals.

Vital signs, including temperature and blood pressure
Neurological examination, focusing on cranial nerve function and signs of increased intracranial pressure
Ophthalmological examination, including fundoscopy to assess for papilledema
Assessment of eye movements and alignment

Imaging: MRI or CT scan of the brain to evaluate for structural abnormalities, such as tumors, abscesses, or signs of increased intracranial pressure.
Lumbar Puncture: To assess cerebrospinal fluid for signs of infection (e.g., meningitis, encephalitis) or inflammation.
Blood Tests: Complete blood count, blood cultures, and tests for infectious diseases (e.g., syphilis, tuberculosis) as indicated by history and examination findings.
Ophthalmological Tests: Formal visual field testing and assessment of visual acuity.