I have to admit.
I can count on one hand the number of headaches I've had in my life. Simply put, I almost never get them. I even had a migraine once where I saw aura (strobe-like lights) but never got the infamous headache afterwards. I quit coffee for a while and everybody warned me about headaches the first day after. While that sounded awful, the headache never arrived.
But even though I don't have much personal experience with headaches I do have a lot of clinical experience seeing patients who get them. During the eye exam, many of those patients become surprised to discover that there are vision problems that can cause them.
Here are five common, yet, highly treatable vision dysfunctions that can cause headaches.
1) Hyperopia (Farsightedness)
Hyperopia - otherwise known as being farsighted, is one of the most common visual dysfunctions in the world. You could call it a 'visual dysfunction' or a 'refractive error' but all it means is that the eyeball is shorter from from front to back. As a result, light focuses behind the eye and the farsighted person has to make a muscle adjustment to bend the light rays.
As long as the person can make the muscle adjustment with ease, they can bring the objects into focus, but if they have to put in effort, this can cause vision to blur and create headaches, especially while viewing close objects. The treatment for Hyperopia is almost always eyeglasses and/or contact lenses.
2) Hyperphoria (Vertical Imbalance)
Hyperphoria is a condition where one eye has a tendency to tilt up higher than the other eye. The muscular effort to counteract this tilt and bring the eyes level can create fatigue and cause a headache. The treatment for this is either eyeglasses with prism, surgery, or vision therapy depending on the case.
3) Convergence Dysfunction
Convergence Dysfunction is when the two eyes either pull inward too much or too little. This is different from a crossed eye or a wandering eye (Strabismus) because the person with the convergence dysfunction can actually keep the eyes physically and cosmetically straight. But in an effort to compensate and keep the eyes coupled together, the person has to use muscular effort. Over time, just like the other conditions discussed here, this can lead to a headache. The treatment for Convergence Dysfunction is Vision Therapy.
4) Accommodative Dysfunction
Accommodative Dysfunction is when the lens in the eye is not quick enough to focus on objects from near to far and back again. When focusing the eyes for varying distances, the eyes have a lens that adjusts and changes shape (just like a camera lens).
When this doesn't work quick enough to meet the demands, then headaches (especially in the front/forehead area) can occur. Another symptom you might observe is a child having trouble focusing on the board to the desk and back again. The treatment for Accommodative Dysfunction is either Vision Therapy or eyeglasses.
5) Presbyopia
One of my old optometry school professors used to joke that there are three certainties in life: Death, Taxes, and Presbyopia. If you are over the age of about 45-50, you'll know what I'm talking about.
Presbyopia is when the lens in the eye gradually stops working so that close range objects begin to blur. The changes associated with presbyopia actually begin in the teenage years but don't actually manifest until your 40's. It just keeps getting worse until you are about 65 when it levels off (good news for the sexagenarians out there). When Presbyopia goes untreated, the eye muscles have to work harder than normal which can lead to headaches. The treatment is again... you guessed it... glasses, or contact lenses.
Important note:
Eye care professionals are not the first specialists you want to see if you are suffering from headaches.
The first step you want to take is to get evaluated with your primary care physician. If they can't find medical reasons for your headaches, go see the eye doctor.