Below is a sampling of some of the more critical studies that have helped medical researchers, doctors, and patients understand the underlying mechanisms of migraines and light sensitivity:
SCIENTIFIC STUDIES ON MIGRAINE, LIGHT, AND GLASSES FOR MIGRAINES
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Study Shows Light Triggers Migraine Pain Even in Blind Subjects
The optic nerve plays a major role in transmitting signals that cause painful sensations in migraine-sufferers – even in people who are blind. Six of the subjects who had no light perception at all due to optic nerve damage or removal also were unaffected by light during their migraine episodes, suggesting the retina plays a role even when the eyes don’t “see.” The remaining 14 subjects were able to detect bright lights directed at their faces, and had significant reactions when light was shone on them during migraine attacks.
Source: Noseda R, Kainz V, Jakubowski M, Gooley JJ, Saper CB, Digre K, Burstein R. A neural mechanism for exacerbation of headache by light. Nat Neurosci. 2010. 13:239-45. http://www.ncbi.nlm.nih.gov/pubmed/20062053
Non-visual Nerve Pathways Can Trigger Light Sensitivity in Blind patients
A study of a blind patient with photophobia, or extreme sensitivity to light, supports the concept that light triggers certain neural pathways unrelated to vision, according to a study from the University of Utah School of Medicine. According to researchers, the 68-year-old patient who developed blindness 20 years earlier as a result of a benign tumor suffered from headaches triggered by light. The researchers hypothesized the patient’s reaction was due to hyperexcitability of the trigeminal nerve, the primary sensory nerve of the head, which other studies have also associated with light sensitivity and migraines.
Source: Amini A, Digre K, Couldwell WT. Photophobia in a blind patient: An alternate visual pathway. Case report. J Neurosurg. 2006. 105:765-8. http://www.ncbi.nlm.nih.gov/pubmed/17121141
Light Sensitivity Is an Important, but Often Undiagnosed Symptom of Migraines
A study from Baylor College of Medicine reveals most patients aren’t aware of increased light sensitivity during migraines, resulting in inaccurate diagnosis. Researchers asked 85 patients with migraine or probable migraine about light sensitivity; 24 percent initially denied being light-sensitive during headaches, but after more detailed questions, 93 percent reported they did experience increased light sensitivity. Researchers say the study underscores the importance of asking detailed questions to help ensure proper diagnosis and care are achieved.
Source: Evans RW, Seifert T, Kailasam J, Mathew NT. The use of questions to determine the presence of photophobia and phonophobia during migraine. Headache 2008;48:395-7. http://www.ncbi.nlm.nih.gov/pubmed/17868350
Migraine Sufferers Are Significantly More Sensitive to Light
People who suffer from migraines are more likely to be sensitive to the effects of bright light and loud sound even when not experiencing headache symptoms, according to a study from the U.K. Researchers compared the responses of 52 migraine patients and 48 non-migraine-sufferers exposed to increasingly greater levels of light and sound, and found the migraine patients had significantly lower tolerance thresholds for both light and sound. The study also found light hypersensitivity increased with older age.
Source: Main A, Dowson A, Gross M. Photophobia and phonophobia in migraineurs between attacks. Headache. 1997. 37:492-5. http://www.ncbi.nlm.nih.gov/pubmed/9329231
Specially tinted Lenses Are Effective in Relieving Migraine Symptoms and Other Photophoba Conditions
A review of photophobia treatments conducted by researchers from the John A Moran Eye Center at the University of Utah Health Sciences Center found FL-41 lenses to be effective in alleviating migraine pain and frequency, as well as overall light sensitivity in patients with photophobia. They suggest patients with migraine are especially sensitive to light with specific wavelengths, and FL-41 lenses help reduce symptoms by filtering out these wavelengths from the light spectrum.
Source: Katz B, Digre K. Diagnosis, Pathophysiology and Treatment of Photophobia. Survey of Ophthalmology. 2016.02.001 http://www.surveyophthalmol.com/article/S0039-6257(15)30007-2/abstract
Special Tinted Lenses Improve Migraine Symptoms and Reduce Frequency of Events
Specially-tinted rose lenses help reduce the frequency, duration and intensity of migraine events in children, according to a study from the U.K. The study evaluated the effects of both rose-tinted and blue-tinted lenses over a four-month period in a group of 20 children who had been clinically diagnosed with migraines. After just one month of wear, children in the study reported a reduction in headache frequency with both types of lenses; however, only those who wore rose-tinted lenses continued to experience this benefit for the entire four-month study period. At the end of four months, the frequency of migraines in children with rose-tinted lenses had dropped from 6.2 per month to 1.6 per month.
Source: Good PA, Taylor RH, Mortimer MJ. The use of tinted glasses in childhood migraine. Headache. 1991. 31:533–6. http://www.ncbi.nlm.nih.gov/pubmed/1960058
FL-41 Lenses Are Superior to Gray- and Rose-tinted Lenses for Preventing Light Sensitivity
According to a pair of studies from researchers at the University of Utah Health Sciences Center, FL-41 lenses, designed to block certain wavelengths associated with light sensitivity, are better than gray- or rose-tinted lenses when it comes to decreasing the effects of light sensitivity in patients with benign essential blepharospasm (BEB). Patients who suffer from BEB, a condition that causes rapid blinking or eyelid spasms, have the same type of light sensitivity issues as people who have migraines. The studies compared the effects of wearing FL-41 lenses, rose-tinted lenses and gray-tinted lenses in a group of 86 patients, including 56 with BEB and 30 healthy controls. At the end of the study, the researchers found the FL-41 lenses reduced both blink rate and eyelid spasms in the BEB groups while also providing superior improvement in light sensitivity and reading compared to the other lenses.
Source: Blackburn MA, Lamb R, Digre KB et al. FL-41 Tint Improves Blink Frequency, Light Sensitivity, and Functional Limitations in Patients with Benign Essential Blepharospasm. Ophthalmology. 2009. 116:997–1001, http://www.ncbi.nlm.nih.gov/pubmed/19410958
FL-41 Lenses Prevent Eye Symptoms Triggered by Fluorescent Lights
An early study of FL-41 lenses provided the first clear indication of the lenses’ ability to reduce photosensitivity symptoms in a wide array of patients with hypersensitivity to light, including people whose symptoms are triggered by exposure to fluorescent lights.
Source: Wilkins AJ, Wilkinson P. A tint to reduce eye-strain from fluorescent lighting? Preliminary observations. Opthamology and Physiological Optics. 1991. 11:172-175. http://www.ncbi.nlm.nih.gov/pubmed/2062542