Our doctors frequently see patients complaining of headaches. While the ultimate cause of a headache may not be determined, patients may be able to better manage and prevent headaches if they understand the factors that may contribute to the onset of the headache. The discussion below differentiates between non-migraine and migraine headaches.
The first step in identifying the reason for headaches is to visit your family doctor. Your doctor will ask questions about the timing, frequency, duration and concurrent symptoms of the headaches, as well as what activities you are doing before and while they occur. The answers to these questions may still not reveal the cause of headaches for even for the most observant patient.
In a small minority of situations, headaches are related to visual problems. The most frequent ocular cause of headaches is when eye muscles are tensed to compensate for eyestrain. The most common reasons for eyestrain are (a) an outdated prescription for eyeglasses or contact lenses, (b) reading large amounts of information for extended periods, (c) reading small print, (d) increased computer usage, (e) reading in dimly-lit areas, and (f) simply trying to overcome poor vision caused by another disease.
In extremely rare situations, headaches are related to primary angle closure glaucoma, a form of glaucoma that affects less than two percent of the population and is generally accompanied by blurred vision, severe pain, redness, nausea and vomiting. However, most forms of glaucoma are symptomless for years until patients start losing a portion of their visual field, so don’t wait for a headache to be screened for glaucoma.
Glaucoma medications or eye drops used to dilate your eyes before an exam may cause headaches. Aside from eyestrain, most patients eventually discover that their headaches are not related to visual problems.
While less frequent than the ordinary headache, ocular migraines, which are also known as ophthalmic migraines, are still quite common. The typical ocular migraine has visual symptoms and may or may not be followed by a headache. If a headache does follow the visual symptoms, it is called a migraine headache.
The exact cause of ocular migraines is unknown. Some researchers have suggested that vascular spasms that cause classic migraines also cause ocular migraines; spasms may affect the blood supply to the vision center in the brain. Food additives, hormonal fluctuations, stress and certain odors may also trigger these migraines. Ocular migraines are common in young people who also experience classic migraines. In addition, as people age they may begin to experience ocular migraines without headaches.
During an ocular migraine, images may appear to be gray or light may appear to be pale pastel colors. Ocular migraines can produce a variety of visual disturbances including flashing lights, jagged lines, blind spots, “heat waves”, and sparkling lights. The visual disturbance either begins in the peripheral vision and moves centrally or begins in the central vision and moves out peripherally. These visual disturbances can last anywhere from 10 minutes to an hour and usually only affect one eye. Typically there are no serious complications caused by ocular migraines, and treatment is not necessary unless accompanied by a classic migraine. The only commonly reported after-effect of ocular migraines is fatigue.
A comprehensive eye exam is recommended to rule out any eye disease as the cause of ocular migraine symptoms.