The Difference Between Headaches and Migraines

Are headaches the same as migraines? Can a migraine cause a vision problem? Can a vision problem cause a migraine? Are headaches a symptom of an eye disease? So many questions!

The distinction between a headache and a migraine can be a little murky. Headache is an umbrella term referring to a number of disorders involving pain in the head, face, or upper neck area. A migraine is a painful primary headache disorder.

Primary vs Secondary Headaches
There are two broad categories of headaches – primary, meaning headaches that do not arise from another medical condition; and secondary, which are those with an underlying cause such as infection or overuse of medications. Migraines are typically considered a form of primary headache and will present with other symptoms not found in the common garden variety headache.

Migraine headaches are attacks of moderate to severe pain in the head, usually occurring on one side of the head only. This being said, there is a type of migraine known as a visual migraine, which occurs without the headache. Though not all people experience migraines the same way, other characteristics of migraines may include:

  • Being accompanied by nausea and vomiting.
  • An early prodrome phase of mood changes, neck stiffness, sensitivity to sensory stimuli such as lights or sounds, that may precede any head pain by days or hours.
  • An aura phase of sensory disturbances occurring just before or during the migraine episode; visual auras include sparkling or flashing lights in the vision, tunnel vision, a kaleidoscope sensation of the vision, or unusual blind spots in the visual field. The aura phase can also involve numbness and tingling of the arms, slurred speech, and mental impairment.
  • The postdrome phase occurs after the headache has dissipated and can last up to several days, leaving the individual feeling generally unwell, confused, and fatigued.
  • Identifiable triggers, such as sleep deprivation, certain foods, stress, alcohol, or hormonal changes.

Though headaches and migraines can be a result of numerous conditions not remotely related to the eyes or vision, because the pain may occasionally feel as if it’s located behind the eyes, or because of the visual disturbances experienced during a migraine attack, many patients will present to an eyecare professional during headache investigations.

Can Headaches Mean Your Glasses Need Updating?
Uncorrected, under-corrected, or incorrectly corrected prescriptions do have the potential to induce a common headache, but the association between spectacle-use and migraine headaches is a little less well established. Evidence of the link between migraines and refractive error in the scientific literature is tenuous at best; a couple of studies have found that those in the migraine study group had a higher degree of astigmatism (a type of refractive error) and anisometropia (a difference in refractive error between the eyes) when compared to the control group who did not experience migraines. The conclusion of both studies was that people with migraines should schedule regular eye tests, a vague statement that really applies to the entire population of both migraineurs and non-migraineurs.

On the other hand, the association between a general headache and optical correction is more well accepted and is typically observed more readily both in practice and in the scientific literature. An incorrect prescription can put unnecessary strain on the visual system as it actively attempts to achieve clear vision, which may manifest in some individuals as a headache. Studies report varying results, as studies tend to do, but in general it has been noted that the lack of correction or incorrect prescribing of optical aids is more prevalent in those who suffer headaches than those who don’t, and the proper correction of refractive error with spectacles or contact lenses can help to alleviate the frequency of headaches, particularly in children.

Can Headaches and Migraines Be Associated with Eye Disease?
There are two aspects of this question, a question within a question (a sort of Inception, one might say) – are headaches a risk factor or cause of eye disease? And are headaches a symptom of eye disease?

If refractive error is considered a disease – and the eye care industry, short-sightedness is now being considered an epidemic condition – then the answer is yes. If refractive error were not considered a disease – well, the answer actually is still yes. Several other eye-related diseases have also been known to present with headache or migraine as a possible symptom or risk factor:

  • Dry eye disease. Studies have found that migraineurs with concurrent dry eye disease suffer from more severe migraine attacks compared to migraineurs without dry eye; dry eye disease was also more prevalent in people with migraines.
  • Glaucoma. Glaucoma is a disease of the optic nerve at the back of the eye with the potential to cause permanent vision loss. The process of damage to the optic nerve itself is typically painless but research has found that a common underlying blood flow disorder may provide a link between glaucoma and the presence of migraines. A subtype of glaucoma known as acute angle closure glaucoma (AACG) may induce head pain during extreme spikes of pressure in the eye. Migraines have also been found to be significantly more common in patients with another subtype of glaucoma, called normotension glaucoma.
  • Inflammatory eye diseases. Such conditions include keratitis (inflammation of the cornea at the front of the eye) and uveitis (an inflammatory disease of the structures within the eye, such as the colored iris). Though the pain originates in the affected eye, some may identify the pain as a headache.
  • Intracranial hypertension (IHT) and papilledema. Here’s one for nightmares – a headache due to a brain tumor. The eye part is from the papilledema, a swelling of the optic nerve as a result of the elevated pressure within the brain. Though brain tumors are not the only cause of IHT, the presence of headaches and papilledema can be a warning sign. 90% of those with chronic IHT report headaches, typically unable to be relieved by usual medications.
  • Giant cell/temporal arteritis. Another condition not technically confined to the eye, giant cell arteritis (GCA) is a disease of the arteries throughout the body and can cause permanent vision loss in one or both eyes. Common symptoms include general unwellness, jaw pain, scalp tenderness, fatigue, and headache.

Headaches and migraines are common conditions, affecting about 1 in 6 Americans and ranking within the top 10 reasons for emergency room visits. It can be difficult to identify the underlying cause of your head pain – reading through this entire article may have been a contributing factor – but along with care by an experienced general practitioner, a comprehensive eye examination may help to point investigations in the right direction.