Eye muscle strain may be a part of the reason for headache pain. A difficulty focusing or looking down and reading is a common sign that you are having trouble bringing your eyes inward. Eye muscle trigger points can develop in the ocular muscles. Neck tension and poor mechanics are an associated finding.
Another common finding after a head injury, concussion or even whiplash is a nerve injury affecting the eye muscles of one or both eyes. This creates a continued strain and eye muscle pain. This can be treated with Physical Therapy and is not usually something that requires an optometry assessment. Most people with this problem have had a normal eye exam. The problem is not with the eye itself but the muscles and nerves that control the eye.
Underlying Causes of Myofascial Trigger Points and Nerve Entrapment of the Ocular Muscles
Whiplash Associated Injury
Head Injury/Post-concussion
Chronic Headaches, Tension Type Headache
Neck Injuries
The problem is not with the eye itself but the muscles and nerves that control the eye
Our theory is that this can occur with clenching and tension to the cranial sutures, most commonly the sphenoid bone. Tension and changes to motion of the upper neck including loss of proprioception or head and joint position sense can also affect the eye muscles.
Symptoms of Ocular Myofascial Trigger Points
Eye fatigue by the end of the day or with increased reading and activity
Pain around or behind your eye or eyes
Eye strain
Dizziness or feeling 'off'
Depth perception issues, driving is more difficult and can be more stressful
Walking grocery aisles, especially the cereal aisle or large stores such as Costco are difficult and cause symptoms
Muscle trigger points in the eye muscles can be felt next to the edge of the orbit along the bone. We do not recommend pushing on the eye itself. Supporting next to the eye where the muscle attachments are and adding head motion can bias the cranial nerves of the eye. Increased pain with testing suggests a cranial nerve entrapment as part of the underlying problem.
The most common muscle involved is the superior oblique muscle of the eye. It is easier to feel this muscle as it goes through a sling on the inside of your eye. It is responsible for inward motion as well as rotating the eye inward.
A study conducted by Cesar Fernandez de la Peñas and colleagues on the palpation of the superior oblique muscles in people suffering with headaches showed that not only was pain greater to this ocular muscle but also more frequently involved the more severe or chronic the headache.
Eye muscle pain and muscle trigger points are very common in tension headaches
Testing Double or Blurred Vision
There are tests that can be done to check to see if your eyes are working together. The most common is to check convergence and divergence. If you see one eye track different than the other than this means that there is a coordination problem and binocular vision is affected.
Convergence/Divergence Testing
Things to look for during a convergence test
Eye switching back and forth. The brain is shutting off one eye or suppressing the vision of one eye at a time. This will cause you to lose your depth perception and requires your brain to work harder.
Eye drift of one eye. When this happens it is pretty obvious. One eye gives up and drifts outwards.
Increased inward eye motion. One eye is pulling in too much giving the perception that the other eye is weaker. In this case the eye that is turning in more has increased tension to the superior oblique.
Maddox Rod Test
Another test to confirm a difference in eye position is the Maddox Rod. This test uses a filter over one eye while shining a light at both. If both eyes are looking at the light then the red line the filter creates appears to be touching the light. If the light and line are separate then one or both eyes are ‘off’ or deviated.
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Remember
Correcting vision issues and eye coordination is possible through manual therapy techniques, and in some cases vision therapy exercises are added. The above tests, including palpation of the ocular muscles, is a screening process to determine that the visual system is involved. Further vision testing with balance and cervical proprioceptive responses, as well as cranial nerve involvement, are done to classify the type of vision issue and how it relates to the cervical spine and vestibular system.
You don’t know what you don’t know (Or what you don’t test)
