Can your eyes cause headaches? When vision is to blame, and when it isn't

Yes, your eyes can cause headaches, but far less often than most people assume. The American Academy of Ophthalmology (AAO) says eye diseases are one of the least common causes of headaches, and that most headaches are not serious and are triggered by things like stress, fatigue, dehydration and certain foods. When the eyes really are to blame, it is usually strain from long stretches of reading or screen work without breaks, or an uncorrected vision problem such as astigmatism or age-related presbyopia after 40, and the headache tends to ease with rest or with glasses in the right prescription. A small number of conditions, however, combine headache with eye symptoms and are emergencies that cannot wait. This guide helps you tell them apart.

Why headaches around the eyes get blamed on eyesight

The first reason is that the most common type of headache is felt around the eyes. According to the AAO, that is tension headache, which happens when the muscles of the scalp and neck tighten, and shows up as pressure or a dull ache in the forehead, the temples and around the eyes. Its triggers include sitting or sleeping in an uncomfortable position, reading or doing other close-up work for a long time without breaks, and clenching the jaw or grinding the teeth. In other words, the pain can sit around the eyes without the eyes being its source. The second reason is that other types of headache come with vision or eye symptoms, so they seem to come from the eyes:

• Migraine: throbbing pain, often on one side of the head, lasting from hours to several days and worse with movement, sometimes with sensitivity to light and sound. The AAO says it affects at least 1 in 10 people and is more common in women.
• Migraine aura: zigzag lines or shimmering, coloured or flickering lights in one side of your vision may come before the pain, or on their own without any pain. These visual symptoms are part of the migraine itself rather than a disease of the eye, but anyone seeing them for the first time needs a prompt medical assessment.
• Cluster headache: severe pain on one side of the head with a red or watering eye on the same side, lasting from 30 minutes to 3 hours, and sometimes returning every day for a month or two. It is less common than tension headache or migraine and affects men more than women.

Eye strain headache symptoms: when the eyes really are the cause

The AAO notes that long periods of uninterrupted near work, such as reading or looking at a computer, are a common cause of eye discomfort, with headaches and blurry vision among its common symptoms. It adds that an incorrect glasses or contact lens prescription can cause blur, and that some people get facial muscle fatigue from squinting for long periods because they are not wearing the correct glasses. It also lists headaches among the symptoms of astigmatism and of uncorrected presbyopia, the loss of close-up focus that usually becomes noticeable shortly after age 40. The reassuring part is that eye strain does not injure the eye or cause permanent damage.

Signs that point towards the eyes as the source:

• The headache starts after long spells of reading, screen work or driving, and eases once the eyes rest.
• It comes with blurred vision, tired or watery eyes, or a need to squint to see clearly.
• You are past 40 and have started holding your phone or book farther away to read.
• It has been a long time since your last eye exam, or you are wearing old glasses or someone else's.

If these signs fit, an eye exam is the first step. A mild headache in the first couple of days with new glasses that then gradually fades is common while you adapt to the new prescription; what calls for a recheck is a headache that shows no improvement after about a week, or that gets worse instead of easing.

Children's headaches: glasses are not always the answer

Many parents assume their child's headaches come from poor eyesight, but the evidence says otherwise. The AAO has reported on a study by paediatric ophthalmologists at Albany Medical Center in New York State, who reviewed the records of children under 18 seen at their clinic for frequent headaches between 2002 and 2011; every child had a complete eye exam. The study found no significant link between frequent headaches and a need for glasses, even when the headaches came on during visual tasks like homework. According to parents' follow-up reports, headaches improved in 75% of the children, or 3 out of 4, and they were just as likely to improve whether or not the child got a new prescription.

None of this means ignoring a child's eyes; an eye exam is still the right first step for frequent headaches. It does mean not expecting glasses to fix the headaches when the exam comes back normal. In that case the paediatrician is the next step, to look at other causes such as sleep, water intake and stress. The AAO advises people with migraines to note down what came before each attack, and the habit helps adults and children alike:

• When the headache started, how long it lasted and where in the head it was.
• What you were doing beforehand: reading, screens, driving or sitting long in one position.
• How many hours you slept, how much water you drank and what you ate that day.
• Any eye symptoms before or during the pain, such as zigzag lights, blur or redness.

Practical steps that cut eye-strain headaches

• The 20-20-20 rule the AAO recommends: every 20 minutes, look at something at least 20 feet (about 6 metres) away for at least 20 seconds.
• Set your screen slightly below eye level so your gaze falls slightly downwards, and avoid lighting that is too dim or too harsh where you work.
• If you have trouble seeing your screen clearly, ask your eye doctor about computer glasses: progressive lenses designed for the usual screen distance of about 20 to 26 inches (roughly 50 to 66 cm).
• Turn air-conditioning vents away from your face at the desk and in the car, and use artificial tears when your eyes feel dry.
• Update your prescription whenever your vision changes, and don't rely on old or borrowed glasses for hours of close work.

Warning signs: when a headache with eye symptoms is an emergency

Although eye diseases rarely cause headaches, the AAO flags a few serious conditions in which headache and vision changes come together, and treats them as emergencies that need medical help right away. Go straight to the emergency department if you notice any of these patterns:

• Sudden severe pain in the eye or forehead, which may come with a red eye, blurred or reduced vision, halos or rainbows around lights, headache, nausea or vomiting. These signs do not all have to appear together: sudden severe eye pain on its own is reason enough to go. They can be symptoms of an angle-closure glaucoma attack, when the pressure inside the eye rises quickly.
• Constant throbbing pain in the temples with scalp tenderness, or jaw pain when chewing or talking, especially after age 50, even if your vision has not changed yet; blurred, double or lost vision makes it even more urgent. These can be signs of giant cell arteritis, and urgent treatment helps prevent vision loss in both eyes.
• A severe headache with a drooping eyelid, and possibly double vision. These can be signs of stroke, one of the most serious causes of headache with vision changes.

In these situations, don't wait for a routine appointment or try new glasses or a painkiller and wait. Any sudden, extremely severe headache unlike anything you have had before also needs emergency care, even without eye symptoms. For frequent or severe headaches in general, the AAO advises telling your doctor, who will ask about your symptoms and medical history, examine you, possibly order tests, and refer you to an eye care provider if your eyes appear to be the cause.