Following a concussion or mild traumatic brain injury (TBI), patients may suffer from light sensitivity or photophobia, making it challenging to return to normal activities and may trigger headaches. A 2017 article published by the University of Cincinnati Department of Neurology and Rehabilitation Medicine reported that “wearing certain colour-tinted lenses may be a good alternative to dark sunglasses.” [1]
The University team addressed the use of dark sunglasses as a problematic solution to light sensitivity. Dark sunglasses, while they reduce the amount of incoming light, are not practical indoors or in low light situations and add to eye strain as the information is dimmed and more difficult to process.
It is similar to wearing noise cancelling headphones to block out an annoying high-pitched sound and then trying to hear a conversation. You would have to strain to hear, leading to more discomfort and difficulties. The solution is not to block all light (or sound) but only the wavelengths of light that you are sensitivity to.
Patients in this study were provided with a wide range of stock filter colours to choose from. The study found that sensitivity to certain wavelengths of light can be reduced with a strategy that includes colour-tinted glasses and that the use of these glasses may aid in the recovery process.
There have now been several formal studies reporting that the photophobia and other visual symptoms following a concussion or brain injury may be alleviated by using precision tinted filters. Precision tinted lenses can provide an effective solution for the management of persistent symptoms such as lingering light sensitivity, confusion, headache, decreased balance and vision disturbances including blurry vision, trouble focusing and sensitivity to patterns.
These symptoms can make it challenging to return to work or school activities where reading printed, and computer-based material is a fundamental requirement for professional and educational success and daily functioning.
A 1996 study provided objective evidence for improvement of visual function provided by light-filtering lenses in patients who become photophobic after TBI. Contrast sensitivity testing and assessment of reading rate added objective criteria for the clinical selection of light-filtering lenses in the treatment of TBI-induced photophobia. [2]
Studies have proposed that the neurological disinhibition, resulting from brain injury, may be responsible for these increased sensitivities. [3] And this disinhibition is similar to the hyperexcitability of Visual Stress.
Additionally, the studies outlined below have reported that precision tinted lenses, or at least a wider range of filter colour options, provided increased visual comfort by reducing sensitivities to lights, improved reading performance, and allowing engagement in medically approved activities while minimizing the risk of symptom exacerbation.
In 2012, an article written by the Chief of Vision Rehabilitation Services at SUNY College of Optometry, and published by the International Brain Injury Association [4], outlined the visual-vestibular symptoms of ABI are all symptoms associated with Visual Stress and the hyperexcitement of the visual cortex, a state which has been demonstrated to be calmed and normalized with the application of precision tinted filters. The study concluded that treatment options include individually prescribed coloured filter lenses and that systems such as Colorimetry provide a systematic approach to determining an appropriate tint or coloured lens overlay.
In a further study by the SUNY College of Optometry 2016 [5], patients used the Intuitive Colorimeter device to select their optimal filter to provide the most comfort and clarity of text. The research team found that most patients with ABI chose a precision tinted filter that resulted in increased visual comfort and concluded that the use of precision tinted lenses would be a reasonable first step to increase comfort and should be considered as an adjunctive treatment in patients with ABI and photosensitivity.
Since 2015 Opticalm has provided individually prescribed coloured filter lenses and other assistive tools such as tuneable colour light bulbs, screen tinting software, and more recently non-LCD computer monitors to help several hundred clients manage their unpleasant physical and visual perceptual symptoms. The majority of these clients, referred to us by their health practitioners, have been suffering from post-concussion vision issues. Clients are carefully screened to ensure that other vision needs are addressed prior to the assessment and symptoms indicate the presence of Visual Stress so that tinted filters will likely be effective. Individually prescribed coloured filter lenses were selected by over 95% of the individuals tested, showing an average 30% rate of reading improvement and a great number of subjective improvements like reduction in headaches and anxiety, increased visual comfort, improved balance, and improved cognitive functioning and alertness.
Considering the overlap of symptoms and the findings of these published papers, it would make sense to investigate for and treat Visual Stress if sensitivities to light and pattern are reported by individuals with post-concussion or post-ABI syndrome.
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Other info: https://www.sciencedaily.com/releases/2017/07/170705132940.htm