It seems hard to believe that the majority of frequent headache sufferers sitting in a neurologist’s office could be solved with glasses. A bigger impact is in the area of asthenopia, which may affect more than 125 million people in the United States alone. The average American spends about 13 hours per day on digital devices, with 59% complaining of eyestrain, making this field an attractive opportunity. So, how do we address it?

Prism is the Answer

One day it’s likely we’ll prescribe prism as an add-on feature for patients suffering from eyestrain (or frequent headaches), just as we might add anti-reflective coatings, blue light blocking or Transitions technology. Who wouldn’t want to be more productive on digital devices or significantly reduce frequent headaches? The problem with traditional prism is that the majority of patients require more prism at near distance and previous options only allowed for a uniform prism correction throughout the spectacle lens… until now.

The Connecting Link

Almost two-thirds of patients in the US experience headaches, dry eye or eyestrain, yet less than 10% mention these to their optometrist.1,2 The link to all of this is the trigeminal nerve, the largest nerve in the brain, responsible for the majority of head, face, jaw, neck and corneal sensations. In a study involving 179 participants with refractory or treatment-resistant chronic headaches, 54% reported their symptoms reduced substantially or basically gone and 81.6% showed a positive response to treatment.3 Based on this data, we can confidently state that more than 50% of patients with chronic frequent headaches can be resolved with contoured prism glasses.

Trigeminal Dysphoria (TD)

This condition involves misalignment of the eyes—in particular exophoria with convergence insufficiency. The compensation required and the proprioception of where the brain thinks the eyes are positioned create conflict and stress on the trigeminal nerve, which is why many patients with traumatic brain injuries also have frequent headaches or other TD symptoms such as headaches, dizziness, dry eye sensation, tired eyes, neck and shoulder pain and photophobia.1 Pain thresholds vary and range from eye strain or tired eyes to frequent, severe headaches. These patients often “decompensate” their trigeminal nerve by going into a dark, quiet room to remove stimuli until the nerve recovers.


Most clinicians are not measuring phorias because the methods such as Von Graefe to cover testing with prism bars are subjective and time-consuming, with inconsistent endpoints. Enter Neurolens technology, which in under three minutes objectively measures horizontal and vertical phorias, fixation disparity, accommodative convergence response and many other parameters that provide an objective, repeatable, accurate prism correction at both near and far distance.

Contoured Prism is Key

Since 90% of patients have a greater prism requirement when fusing at near, contoured prism increases by 0.75 BI as you move from far to near through the spectacle lens.4 This prevents prism creep, variability and relieves asthenopia and frequent headaches far more often than standard prism. Even small amounts of contoured prism correction can yield profound symptom relief. Symptoms ranging from headaches, dry eye sensation, neck stiffness and asthenopia are shown to improve by more than 77.8%, with dizziness improving by almost 90%, according to company data.5 Concerning productivity, patients wearing Neurolenses improved their reading speed by 70%.

Ocular-related headaches are a relatively new field of understanding, but the effects of treating eye misalignment with contoured prism (and/or binocular vision training) are significant and life-altering. I’ve witnessed this in hundreds of patients and three family members, including one whose frequent migraines went from five to 10 per month down to one to two per year! 

Dr. Karpecki is medical director for Keplr Vision and the Dry Eye Institutes of Kentucky and Indiana. He is the Chief Clinical Editor for Review of Optometry and chair of the New Technologies & Treatments conferences. A fixture in optometric clinical education, he consults for a wide array of ophthalmic clients, including ones discussed in this article. Dr. Karpecki's full list of disclosures can be found here.

1. Liu S, Dong H, Fang S, Zhang L. Risk of dry eye in headache patients: a systematic review and meta-analysis. Ann Med. 2022;54(1):2876-85.

2. Ismail OM, Poole ZB, Bierly SL, et al. Association between dry eye disease and migraine headaches in a large population-based study. JAMA Ophthalmol. 2019;137(5):532-6.

3. Carol Nelson, MD, American Academy of Optometry. October 2019, Orlando FL.

4. Nguyen E, Inger H, Jordan C, Rodgers D. Ocular causes for headache. Semin Pediatr Neurol. 2021;40:100925.

5. Neurolens. Data on file.