Differential Diagnosis for Left Eye Pain without Redness, Drainage, or Injury

Single Most Likely Diagnosis

• Tension headache or migraine: These conditions can cause unilateral eye pain without any visible signs of inflammation or infection. The pain is often described as a dull ache or pressure and can be accompanied by other symptoms like photophobia or sensitivity to sound.

Other Likely Diagnoses

• Dry eye syndrome: This condition can cause eye pain, especially if the dryness is severe. It might not always present with redness, especially in mild cases.
• Sinusitis: Sinus infections can cause referred pain to the eyes, especially if the ethmoid or frontal sinuses are involved. The pain can be unilateral and might not be accompanied by other symptoms like redness or discharge.
• Optic neuritis: This is an inflammation of the optic nerve that can cause eye pain, especially with movement of the eye. It might not always present with redness or other visible signs of inflammation.

Do Not Miss Diagnoses

• Acute angle-closure glaucoma: Although this condition typically presents with redness and vision changes, it can occasionally present without these symptoms. It is a medical emergency that requires prompt treatment to prevent permanent vision loss.
• Temporal arteritis: This condition can cause unilateral eye pain and is a medical emergency due to the risk of vision loss. It often presents with other symptoms like jaw claudication or scalp tenderness, but these might not always be present.
• Orbital cellulitis: While this condition often presents with redness and swelling, it can occasionally present without these signs, especially in early stages. It is a serious infection that requires prompt antibiotic treatment.

Rare Diagnoses

• Scleritis: This is an inflammation of the sclera that can cause severe eye pain. It is less common than other conditions like episcleritis and can present without significant redness in some cases.
• Uveitis: This is an inflammation of the uvea and can cause eye pain, sensitivity to light, and vision changes. It might not always present with redness, especially if it is posterior uveitis.
• Trigeminal neuralgia: This condition can cause sudden, severe pain in one side of the face, including the eye area. It is less common and might be considered if other diagnoses have been ruled out.