Cluster Headache: Characterized by severe, unilateral orbital or periorbital pain, often described as sharp or burning, and can be accompanied by autonomic symptoms such as lacrimation, nasal congestion, or ptosis. The pain behind the eye and the sharp, intermittent nature of the pain are classic for cluster headaches.

Migraine: Can present with unilateral pain, including temple pain, and may involve pain behind the eye. Migraines are often accompanied by other symptoms such as photophobia, phonophobia, and sometimes an aura.
Tension-Type Headache: Although typically bilateral, tension-type headaches can occasionally present unilaterally and involve the temples. The pain is usually described as a band or a squeezing sensation but can sometimes be sharp.
Temporal Arteritis (Giant Cell Arteritis): This condition can cause sharp, intermittent pain in the temples, especially in older adults. It may also involve pain behind the eye due to ischemic optic neuropathy or other ocular manifestations.

Acute Angle-Closure Glaucoma: A medical emergency that presents with severe, unilateral eye pain, often accompanied by blurred vision, nausea, vomiting, and sometimes pain in the temple area. The high intraocular pressure can cause pain behind the eye.
Temporal Arteritis (Giant Cell Arteritis) with Visual Symptoms: As mentioned, this condition can lead to serious complications, including blindness, if not promptly treated. The presence of jaw claudication, scalp tenderness, or visual disturbances alongside temple pain is particularly concerning.
Cavernous Sinus Thrombosis: A rare but potentially life-threatening condition that can cause severe headache, including temple pain, along with symptoms such as fever, ptosis, and cranial nerve palsies.

Trigeminal Neuralgia: Characterized by sudden, severe, shock-like pain around the eyes, lips, or nose mainly because of abnormal blood vessels pressing on the trigeminal nerve in the head. It's less likely to be confused with temple pain but can involve the area behind the eye.
Hemicrania Continua: A rare headache disorder that causes continuous, often severe pain on one side of the head, including the temple area, and can involve pain behind the eye. It's accompanied by autonomic symptoms and is exquisitely responsive to indomethacin.
Sphenoid Sinusitis: Infection or inflammation of the sphenoid sinus can cause deep, midline facial or head pain, including pain behind the eyes, but it's less commonly associated with sharp, intermittent temple pain.