What our eyes can have to do with headaches

When focusing doesn’t work

For our eyes to produce a sharp image, a complex process occurs that we normally do not notice. The eyes constantly focus on the objects we look at, similar to how a camera works. Eye experts call this process "accommodation", which means “adjustment”. Our eye lenses are flexible and connected to tiny muscles that change the shape of the lenses by contracting or relaxing. This creates a sharp image on our retina, allowing us to see near and distant objects clearly. The commands telling the eye to focus come from the brain, which processes the images as they arrive and makes any corrections, if needed.

The accommodation process can become disrupted, for various reasons. Sometimes, the muscles take several attempts to achieve a sharp image. In other cases, there might be excessive tension in the muscles, leading to “over-accommodation”. Over-accommodation can even cause spasms in the fine muscles. Affected individuals may struggle to see objects clearly. Rapid shifts between near and distant views may be impossible or take much longer than usual. This leads to eye strain and headaches because both the eye muscles and the brain become overwhelmed.

Blurred vision and being unable to see what’s going on around you can be very unsettling and stressful. To compensate for visual disturbances as effectively as possible, glasses must be precisely fitted. “Accommodation exercises” are also recommended, which involve training the coordination of both eyes and strengthening the focusing muscles, helping them to work faster and better for a clear image. Ideally, practicing these exercises can stop vision problems from getting worse.

Overworked eyes

If a vision problem (like nearsightedness or farsightedness) goes unrecognized for an extended period, the eyes are subjected to constant excessive strain, often leading to headaches. Similarly, if eyesight deteriorates gradually even with corrective lenses, headaches may arise. That is why it is important to see an eye doctor for regular eye examinations.

Even perfectly functioning eyes can become overwhelmed. Prolonged reading or close work that requires precise focusing puts a lot of strain on the optic nerve. Poor lighting or excessively bright light can also lead to headaches.

Convergence excess

Convergence excess is a condition in which the eyes do not work together properly. If your two eyes turn in (converge) more than necessary when you focus on an object up close, you may find yourself moving the object closer to your eyes. This over-convergence puts your eyes in a squinting position that is very exhausting to maintain.

Convergence excess symptoms mainly occur when your eyes are forced to focus for long periods on objects up close. Extending reading on paper or screens and other computer work are common causes. Because the eye-brain combination is constantly being overworked, headaches soon set in. Additionally, when concentrating hard, people often do not notice if their head, neck, and shoulders are in awkward positions. Staying in uncomfortable positions for too long causes muscular stress, which is another risk factor for headaches.

Dry eye syndrome

Keen readers may also be familiar with a condition called dry eye syndrome (DES). Another medical term for it is “keratoconjunctivitis sicca” (from the Latin siccus, ‘dry’). Dry eye syndrome happens when you don’t have enough tears to lubricate your eyes. Symptoms include dryness, burning, itching, eye pain and vision problems. Dry eyes may also lead to headaches, nausea and dizziness.

Conversely, headache disorders make a person much more likely to develop dry eye syndrome. This has been shown in a large research study. The researchers looked at the proportion of patients with migraines, tension-type headaches and cluster headaches who also had dry eye. The risk of dry eye syndrome was highest among those with migraines, followed by people with cluster headaches. However, above-average rates of DES were also noted in people with tension-type headaches.

When “snow” obscures vision

Visual snow syndrome (VSS) is a vision disorder often reported in people who also suffer from migraines. Patients describe seeing a kind of static (“visual snow”) in their field of vision: they see many small particles, flecks or dots moving like snowflakes across the image provided by the eye. Because it often occurs alongside migraines, VSS was previously thought to be related to visual disturbances that happen during a migraine aura. However, this has not been confirmed in recent research. Both VSS and migraine aura show excessive excitability of nerve cells in the cerebral cortex, but VSS is classified as a separate condition with symptoms that can extend beyond those of a migraine aura.

Some people with the condition have trouble with night vision. Affected individuals may report severely limited night vision, double vision, or “afterimages”, which are perceptions of objects that are no longer in their field of view. Consequently, dizziness and headaches may occur, as the brain is required to work excessively hard, depleting its resources.

Research into treatment options for this debilitating condition is still in its early stages. However, there is hope from new non-drug treatment approaches within mindfulness-based cognitive therapy. This relatively new treatment method combines elements of stress reduction with cognitive behavioral therapy (CBT). CBT has long been successfully used for the prevention and treatment of headache disorders, as well as in other areas.

Where does it hurt?

Distinguishing between eye and headache pain can be challenging. For instance, headaches felt “behind the eye” may actually be eye pain. Eyes can be painful for many reasons. Even minor injuries to the cornea can cause severe pain. Allergic reactions often lead to pain in the eyes, in addition to itching and redness. Inflammatory diseases affecting the eye muscles or other parts of the eye are also possible.

The close proximity of the eyes to the brain and the exceptional interaction between our organs of vision and our nervous system may increase pain sensitivity, ultimately leading to headaches. In this process, the body’s pain-enhancing signaling pathways become more active, while its pain-blocking signals weaken.

Pain prevention and relief

Anyone with a vision impairment should have regular check-ups with an eye doctor to monitor their eye health and adjust corrective lenses as needed. This enables timely responses to changes and helps prevent deterioration. Those experiencing eye discomfort without a known cause should see a specialist to obtain an accurate diagnosis.

To prevent eye strain in daily life, it is also essential to give the eyes opportunities to rest, even if you do not have a vision impairment. Especially if reading or screen work requires close focus, take regular breaks and look at something else to offset the effects. Gazing into the distance (looking out a window, for example) relieves the optic nerves and stimulates other regions of the fine eye muscles. Closing your eyes for a few moments while slowly breathing in and out can also be very relaxing.

It is important to arrange the workplace to optimize conditions for the eyes. If working on a screen, the distance should be properly adjusted. The same applies if working on a laptop on the go. When reading a book, it is essential to avoid bringing the text too close to the eyes. Proper lighting is also crucial. Daylight may seem more comfortable than artificial light. However, lighting conditions can change quickly depending on the weather. This puts a lot of strain on the eyes. Lighting in general should not be dim, in order to ensure that content is easy to see. However, excessive brightness can also be a burden, especially for migraine sufferers. Some individuals are particularly sensitive to the flickering light from fluorescent bulbs.

Identifying specific factors that trigger discomfort can help in making adjustments to your daily routine. Regular breaks remain essential. You may find the reminder feature on the Prevent Headache app useful to prompt you to take short, regular breaks. Interrupting work to change your posture, giving your eyes a chance to rest, and relieving tension in the shoulders, neck, and the rest of the body can help prevent headaches. Regular stretching and gentle movements are effective ways to relieve tense muscles. When we are deeply focused, we often don’t realize how long we’ve been staring in one place.

Intentional, longer relaxation periods with closed eyes also support recovery for both the eyes and the head. Progressive muscle relaxation has proven particularly effective in practice. The prevent-headache.org website and app has a short version that’s easy to incorporate into your daily routine. Regular exercise, preferably outdoors, helps relax the nervous system and gives your eyes a break from the demands of doing close-up work. By gradually incorporating these practices into your daily routine, you can do a lot for your eyes and head.