J Neurol (2012) 259:1832–1839 pattern glare in the susceptible individual are present within standard text documents formed by the individual rows of words separated by the successive spacing between rows [3, 9, 10]. The spatial frequency of this alternating high contrast pattern, formed by text, has been shown to fall within the range known to generate pattern glare symptoms [11]. This is coupled with striped patterns formed by letter strokes in individual words, as well as the vertical strokes of letters that also have a spatial frequency falling within a range sufﬁcient to generate pattern glare symptoms in susceptible individuals. Although the origins of pattern glare and visual stress are equivocal, it is thought that these effects arise due to cortical hyper-excitability [2, 7, 12–14]. Pattern glare has been shown to be associated with a range of neurological conditions including photosensitive epilepsy [15], migraine [13, 16, 17], dyslexia [18–21], autism [22], multiple sclerosis [23], as well as MISViS [24, 25]. Hitherto, there is little evidence detailing the existence of pattern glare in other neurological conditions, such as stroke. Some evidence has emerged from symptom-based investigation, where patients with traumatic brain injuries, including stroke, have demonstrated visual perceptual symptoms, which include light-sensitivity, strain, fatigue and reading difﬁculties which were subsequently reduced with the intervention of optimally selected tinted spectacle lenses [26]. Other reports have recognized a susceptibility to photophobia following traumatic brain injury and these individuals have shown improvements in reading ability with the use of photochromic ﬁlters [27]. Further evidence recognizes that many brain injury patients, including those with stroke, have difﬁculty with reading, such as skipping lines of text, and difﬁculty moving to the next row of print, albeit with the suggestion that these problems arise from motor rather than sensory origin [28]. It has been shown that even following minor head injuries, particularly those involving concussion, subjects demonstrate a lowered tol- erance to brightness and sound [29]; this is supported by earlier evidence of photophobia and sound sensitivity in patients with closed head injury [30]. Measures of critical ﬂicker frequency have also been found to be elevated in those with mild traumatic brain injury, with accompanying symptoms of light and motion sensitivity. It has been proposed that neurological disinhibition, as a result of the brain injury, may cause the subjective hypersensitivity to light and motion in these individuals [31]; this theory supports earlier work, which demonstrated hyperexcit- ability in the visual cortex, in patients with homonymous hemianopia, following stroke [32]. Stroke is the second leading cause of mortality, accounting for 9% of all deaths around the world, and is major cause of disability. The average age-adjusted stroke 1833 mortality for developed countries is around 50–100 per 100,000 people. With the burden of an ageing population, these ﬁgures are expected to increase greatly in the next two decades [33]. Considering the paucity of literature to date, it would seem logical to determine if there is an association between pattern glare and stroke. Conse- quently, the purpose of this study is to measure pattern glare susceptibility in stroke subjects as determined by the pattern glare test. Methods Twenty stroke participants were recruited along with an equivalent number of age and gender-matched control subjects. Suitable candidates for this project were recruited by displaying notices at the research venue (the optometric practice of the investigator) requesting volunteers. Several participants were also recruited following contact with the local Stroke Association group. All candidates had been discharged from the care of the hospital department involved in the treatment of their stroke. The stroke par- ticipants consisted of 11 females and nine males with an age range of 38–85 years (mean 66.4 SD 13.43 years). The control participants had an age range of 36–84 years (mean 57.9, SD 13.91 years) consisting of 11 females and nine males. These groups were calculated as being age-matched (unpaired t test: t = 1.813, df = 38, p = 0.078). The time since the stroke (or most recent stroke) had a range of 0.83–12 years (mean 4.66, SD 3.31 years). Prior to com- mencing the research, ethical approval was obtained from Aston University’s Audiology/Optometry Research Ethics Committee with the study designed to follow the tenets of the Declaration of Helsinki. Each subject was given detailed information regarding the nature of the study, both verbally and in written form; this allowed informed consent to take place prior to their participation. The participants were required to complete a short questionnaire to ensure that they met the inclusion criteria. This was also necessary to pre-determine if any of the subjects had conditions that could potentially predispose them to pattern glare, e.g., migraine. Crucially, they were asked to conﬁrm if they had suffered from any epileptic seizures, as this was the prin- cipal exclusion criterion for the study. Subjects were also asked to conﬁrm if they were dyslexic, autistic, or suffered from multiple sclerosis, or migraine. All subjects demon- strated that they were able to read N8 sized print at 40 cm with their habitual spectacle correction, prior to undertak- ing the pattern glare test. From the initial questionnaires, two migraine sufferers were identiﬁed within the stroke participants and three migraine sufferers within the control subjects. None of the subjects in either group reported a diagnosis of dyslexia, autism, multiple sclerosis or 123