Headache in the left eye may have a variety of causes, including migraines, sinus infection and glaucoma. But there are also a variety of less common causes.
Headaches located behind the eye can result from a number of benign conditions, but it's important to keep in mind that some serious conditions can cause this symptom as well. We'll explore the most common causes first and identify those that should prompt medical intervention.
If you are experiencing serious medical symptoms, seek emergency treatment immediately.
According to the Migraine Research Foundation, migraine is the third most prevalent disorder in the world 8. It affects 18 percent of women and six percent of men in the U.S. Migraine is characterized by pounding, one-sided pain that can sometimes be felt around the eye.
It's associated with sensitivity to light and sound, and aggravated by movement. Sometimes people with migraines experience nausea and vomiting. Migraine attacks can last from several hours to several days. A number of medications are available to treat migraines.
2. Sinus Infection
Sinus infections can cause pain in or around either eye. There may also be tearing. If the infection has spread beyond the sinuses then the person may experience fever and chills. Because most sinus infections are viral, they do not typically require antibiotics.
Glaucoma affects 3 million Americans, according to the Centers for Disease Control and Prevention, and is the second leading cause of blindness in the U.S. It is the most common cause of blindness for people of Hispanic and African descent.
Glaucoma is characterized as a set of disorders in which there is progressive damage to the optic nerve, which carries signals between the eye and the brain. This damage is associated with increased pressure within the eye.
People with glaucoma can experience headache, eye pain, sensitivity to light, nausea and vomiting 10. If this occurs, emergent referral to an ophthalmologist is necessary due to the risk of vision loss.
4. Inflammation and Infection of the Orbit
Inflammation and infection of the orbit (the eye and the surrounding tissues) could also cause eye pain and potentially headache. One example is inflammation of the cornea, or keratitis. This can be caused by infection with viruses or bacteria, exposure to chemicals or UV light, or due to an inflammatory disorder. Urgent treatment by an ophthalmologist is necessary.
5. Giant Cell Arteritis
Symptoms can include:
- eye pain
- blurred vision
- double vision
- or loss of vision,
- pain with chewing
Fever, stiffness and muscle pain may also be present. Treatment of giant cell arteritis is an emergency due to the risk of blindness.
6. Cluster Headaches
Cluster headaches cause severe pain in one eye, usually lasting 15 to 45 minutes but sometimes up to three hours 12. Multiple headache attacks occur each day. Other symptoms include nasal congestion, runny nose and sweating of the face.
The Horner syndrome may also occur; this involves drooping of one eyelid, small pupil, and unequal size of the pupils between the two eyes 11. Cluster headaches are more common in young men and in those who use tobacco and alcohol 12. Medications are available to treat the symptoms.
7. Optic Neuritis
Optic neuritis, or inflammation of the optic nerve, can cause symptoms like eye pain worsened by eye movement, loss of visual acuity and decreased color vision. People over 40 with this problem are more likely to have giant cell arteritis, whereas those under 40 are more likely to have a disease like multiple sclerosis. Either way, urgent evaluation and treatment is needed.
8. Trigeminal Neuralgia
Trigeminal neuralgia is a rare disorder involving the trigeminal nerve, which carries sensation from the face and forehead. Attacks of trigeminal neuralgia consist of extremely severe shock-like or burning pain in the areas supplied by the trigeminal nerve.
The pain can last from seconds to minutes, sometimes occuring repeatedly for two hours. While treatments are available, they are not always effective and the condition can progress.
Less Common Causes
Other blood vessel problems can be less common causes of headache with left eye pain. After having a stroke involving certain arteries in the brain, up to 25 percent of people experience pain in the eye on the same side as the stroke. Blood clots or tears in the carotid artery in the neck could result in eye pain, but usually have other associated symptoms (like a Horner's syndrome).
Brain hemorrhages due to trauma or ruptured aneurysms could lead to eye pain, though again there would generally be other symptoms. Finally, sinus infections rarely result in a clot within a vein in the brain called the cavernous sinus. Cavernous sinus thrombosis produces headache and eye pain but also trouble moving the eye, sensitivity to light, protrusion of the eye, and swelling around the eye.
Brain tumors and tumors that have metastasized to the eye can also potentially cause left eye pain and headache. However, conditions such as brain tumors that increase the pressure in the head often produce headache on both sides.
Warnings and Precautions
Headache with left eye pain can be a medical emergency.
Optic neuritis, or inflammation of the optic nerve, can cause symptoms like eye pain worsened by eye movement, loss of visual acuity and decreased color vision. Blood clots or tears in the carotid artery in the neck could result in eye pain, but usually have other associated symptoms (like a Horner's syndrome). Brain tumors and tumors that have metastasized to the eye can also potentially cause left eye pain and headache.
- Silberstein, S. Migraine. Merck Manual: Professional Version. June 2018. Accessed April 2019.
- Fiore D, Pasternak A, Radwan R. Pain in the Quiet (Not Red) Eye. Am Fam Physician. 2010 Jul 1;82(1):69-73.
- Headache Classification Committee of the International Headache Society: The International Classification of Headache Disorders, 3rd ed. Cephalalgia. 2018, Vol. 38(1) 1–211
- Fried, M. Sinusitis. Merck Manual: Professional Version. February 2019. Accessed April 2019.
- Rhee, D. Overview of Glaucoma. Merck Manual: Professional Version. August 2017. Accessed April 2019.
- National Organization for Rare Diseases. Giant Cell Arteritis. National Organization for Rare Diseases. 2007. Accessed April 2019.
- Facial Pain Association. What is Trigeminal Neuralgia? Facial Pain Association. 2019. Accessed April 2019.
- Migraine Research Foundation: Migraine Facts
- CDC: Don't Let Glaucoma Steal Your Sight!
- Glaucoma.org: Symptoms of Open-Angle Glaucoma
- National Organization for Rare Diseases: Horner’s Syndrome
- Mayo Clinic: Cluster Headaches