Pattern-Induced Visual Discomfort and Anxiety in Migraineurs: Their Relationship and the Effect of Colour

In migraineurs, coloured lenses were found to reduce the visual stress caused by an aversive pattern known to trigger migraines by 70%, but do such patterns also produce a low-level anxiety/fear response? Is this response lessened by colour? We sought to investigate this in a study comprising a broad screening component followed by a dot-probe experiment to elicit attentional biases (AB) to aversive patterns. Undergraduate psychology students completed headache and visual discomfort (VD) questionnaires (N = 358), thereby forming a subject pool from which 13 migraineurs with high visual discomfort and 13 no-headache controls with low visual discomfort, matched on age and sex, completed a dot-probe experiment. Paired stimuli were presented for 500 ms: aversive achromatic 3 cpd square wave gratings vs control, scrambled patterns. These conditions were repeated using the colour that was most comfortable for each participant. VD was greater in the more severe headache groups. On all measures, the migraineurs were more anxious than the controls, and a positive relationship was found between VD and trait anxiety. The 3 cpd gratings elicited an aversive AB in the migraine group which was somewhat reduced by the use of colour, and this was not seen in the controls. The results suggest a new role for colour in reducing visual stress via anxiety/fear reduction.

Assessment of working conditions and informational loads on car drivers

The article provides an overview of risk factors that are caused by the working conditions of car drivers and provides an example of a methodology for assessing visual loads that were measured using a digital video recorder. To assess real visual loads on a car driver, a method for simultaneous recording of information of visual load and heart rate has been developed and tested. The proposed method made it possible to establish a correlation between the dynamics of the flow of visual traffic information and the response of the driver’s body in the form of response changes in the pulse. The effectiveness of the method was shown and the correlation of video fragments and pulsograms with R = 0.4 was established. The results of the work are applicable to assess the working conditions of car drivers, when visual stress is a leading factor in working conditions, in order to prevent fatigue and road traffic accidents.

Visual stress responses to static images are associated with symptoms of Persistent Postural Perceptual Dizziness (PPPD)

BACKGROUND: Images that deviate from natural scene statistics in terms of spatial frequency and orientation content can produce visual stress (also known as visual discomfort), especially for migraine sufferers. These images appear to over-activate the visual cortex. OBJECTIVE: To connect the literature on visual discomfort with a common chronic condition presenting in neuro-otology clinics known as persistent postural perceptual dizziness (PPPD). Sufferers experience dizziness when walking through highly cluttered environments or when watching moving stimuli. This is thought to arise from maladaptive interaction between vestibular and visual signals for balance. METHODS: We measured visual discomfort to stationary images in patients with PPPD (N = 30) and symptoms of PPPD in a large general population cohort (N = 1858) using the Visual Vertigo Analogue Scale (VVAS) and the Situational Characteristics Questionnaire (SCQ). RESULTS: We found that patients with PPPD, and individuals in the general population with more PPPD symptoms, report heightened visual discomfort to stationary images that deviate from natural spectra (patient comparison, F (1, 1865) = 29, p < 0.001; general population correlations, VVAS, rs (1387) = 0.46, p < 0.001; SCQ, rs (1387) = 0.39, p < 0.001). These findings were not explained by co-morbid migraine. Indeed, PPPD symptoms showed a significantly stronger relationship with visual discomfort than did migraine (VVAS, zH = 8.81, p < 0.001; SCQ, zH = 6.29, p < 0.001). CONCLUSIONS: We speculate that atypical visual processing –perhaps due to a visual cortex more prone to over-activation –may predispose individuals to PPPD, possibly helping to explain why some patients with vestibular conditions develop PPPD and some do not.

Exploring the Interaction Between Head-Supported Mass, Posture, and Visual Stress on Neck Muscle Activation

Objective Assess neck muscle activity for varying interactions between helmet, posture, and visual stress in a simulated “helo-hunch” posture. Background Military aviators frequently report neck pain (NP). Risk factors for NP include head-supported mass, awkward postures, and mental workload. Interactions between these factors could induce constant low-level muscle activation during helicopter flight and better explain instances of NP. Method Interactions between physical loading (helmet doffed/donned), posture (symmetric/asymmetric), and visual stress (low/high contrast) were studied through neck muscle electromyography (EMG), head kinematics, subjective discomfort, perceived workload, and task performance. Subjects ( n = 16) performed eight 30-min test conditions (varied physical loading, posture, and visual stress) while performing a simple task in a simulated “helo-hunch” seating environment. Results Conditions with a helmet donned had fewer EMG median frequency cycles (which infer motor unit rotation for rest/recovery, where more cycles are better) in the left cervical extensor and left sternocleidomastoid. Asymmetric posture (to the right) resulted in higher normalized EMG activity in the right cervical extensor and left sternocleidomastoid and resulted in less lateral bending compared with neutral across all conditions. Conditions with high visual stress also resulted in fewer EMG cycles in the right cervical extensor. Conclusion A complex interaction exists between the physical load of the helmet, postural stress from awkward postures, and visual stress within a simulated “helo-hunch” seating environment. Application These results provide insight into how visual factors influence biomechanical loading. Such insights may assist future studies in designing short-term administrative controls and long-term engineering controls.

The clinical significance of a controlled visual exercise regimen for the progression of school myopia

Purpose. Analysis of the dynamics of the progression of myopia with observance and non-observance of the rules of visual work in primary school students. Material and methods. There were 40 children under supervision. The age at initial treatment was 8-10 years. All children were diagnosed with acquired myopia of mild degree from 1.0 to 3.0 D upon treatment. The children were observed for three years. At the first visit, the child's parents were explained in detail the mechanisms of the onset of school myopia, in particular, they focused on two reasons – bowed head syndrome and infinity of visual work, taking into account the use of gadgets. Results. For the analysis, 2 observation groups were formed. 1st group – 20 children (40 eyes), who strictly adhered to the rules of visual work at close range. The 2 nd group of children (20 people, 40 eyes) continued, despite the doctor's recommendations, to adhere to their usual way of life. When analyzing the results of the examination in the 1 st group of children, it was found that over 3 years of observation, all children showed a tendency towards a slow progression of myopia. This was expressed in the annual increase in the length of the anteroposterior axis (APA) of the eye by an average of 0.2 mm, which corresponded to an increase in refraction by no more than 1.0 D. In patients of the 2 nd group, over 3 years of follow-up, there was a significant progression of myopia with an annual increase in the length of the APA of the eye by an average of 0.5 mm, which corresponded to an increase in refraction by 3.5 D. Conclusion. This analysis showed that there are simple, affordable, inexpensive, non-surgical, but effective ways to prevent the progression of myopia, which makes it possible to reduce the likelihood of a rapid progression of myopia by 2.5 times. Key words: progression of myopia, anteroposterior axis of the eye, refraction, school myopia, visual stress regime.

Stress Out: Translating Real-World Stressors into Audio-Visual Stress Cues in VR for Police Training

Virtual Reality (VR) training has become increasingly important for police first responders in recent years. Improving the training experience in such complex contexts requires ecological validity of virtual training. To achieve this, VR systems need to be capable of simulating the complex experiences of police officers ‘in the field.’ One way to do this is to add stressors into training simulations to induce stress similar to the stress experienced in real-life situations, particularly in situations where this is difficult (e.g., dangerous or resource-intensive) to achieve with traditional training. To include stressors in VR, this paper thus presents the concept of so-called ‘stress cues’ for operationalizing stressors to augment training in VR simulations for the context of police work. Considering the level of complexity of police work and training, a co-creation process that allows for creative collaboration and mitigation of power imbalances was chosen to access the police officers’ knowledge and experience. We assert that stress cues can improve the training experience from the trainer’s perspective as they provide novel interaction design possibilities for trainers to control the training experience. E.g., by actively intervening in training and dynamically changing the interaction space for trainees which also improves the trainee’s experience. Stress cues can also improve the trainee’s experience by enabling personalizable and customizable training based on real-time stress measurements and supplementing information for improved training feedback.

Results of Applying the Method of Visual Fatigue Prevention Using Low-Intensity Laser Radiation

Summary. Introduction: Visual fatigue is caused by changes in the muscular apparatus and retina of the eye and is characterized by deterioration in their functional activity. Along with an increase in work experience and age, workplace visual stress promotes the loss of performance. Known methods of visual fatigue prevention and eye strain relief are ineffective. In this regard, a technique of relieving visual fatigue using scattered low-level red laser radiation was developed and patented. The purpose of our study was a retrospective evaluation of effectiveness of the visual fatigue reduction technique. Materials and methods: We examined two groups of women (PC operators and jewellers) aged 43–57 years experiencing visual stress at work and practicing the method under study over the previous 20 years. The state of daylight vision was assessed by adaptation time. Results: A five-day testing of the method of visual fatigue relief showed stabilization of the light sensitivity threshold throughout the work shift. Over the 20-year period, the female workers had had no complaints of eye strain, burning or lacrimation. Objective studies of the functional state of the organ of sight showed that the light sensitivity threshold during the working day in two study groups was significantly lower than that in the control group with no preventive measures taken. Conclusions: We established that using the technique of eye strain relief based on a two-minute binocular exposure to red laser radiation with the power density of 2×10–7 W/cm2, a 5-day course every six months over the period of 20 years, helped retain retinal activity in terms of light sensitivity, thus preventing visual fatigue.

Chromatic Effect Reproduction of Irlen Colored Filters by a Pulse Width Modulation-Driven Three-Chromatic Light Emitting Diode Device

Visual Stress (VS) is an abnormal visuoperceptual condition caused by an imbalance in light adaptation ability which yields reading deficits. It was first described in 1983 and, since then, has been treated with the usage of colored spectral filters, either as Irlen overlays either as lenses for symptoms relief. However, the limited options of overlays compromise the pursuit for the patient’s optimal filter so that a device that could provide a broader range of colors would improve achievements for both screeners and patients. The present work aims to develop a micro-controlled RGB LED device whose goal is to reproduce Irlen overlays combinations chromaticities through colored light metamers. Such a device can open possibilities for better diagnosing Visual Stress (VS) by providing screeners a much more extensive range of colors than regular overlays and glasses and, therefore, allowing more accurate scrutiny of the optimal chromatic point for the patient. For the pursuit of this goal, a LED controller based on PWM (Pulse Width Modulation) of currents was built, and a color reproduction methodology was developed to ensure chromaticity matching. From the 47 filters considered, 22 showed a ratio ΔE/JND < 6 and, thus, laid within a range that could provide the reading performance associated with its corresponding filter. Reproduction methodology was effective and demanded 5 main inputs: LED individual and white point color coordinates plus LED characterization curves. The controller proved to be effective for color manipulation inside the device’s gamut, which opens the possibility for both readjustment of the chromaticity, if it is found to vary with patient’s aging, and further connection to an eye tracker to shorten the search for the optimal point.

Issues of Supplemental Support in Pediatric Ophthalmology

The ophthalmologist often raises the issues about using of various vitamins, trace elements and other nutrients for the prevention and treatment of the different ocular diseases at their practice. The significance of this problem is caused by the importance of the vision for the socialization of modern person, as well as the high intensity of the visual analyzer using both in the process of performing professional occupation and in the usual indoor/outdoor activities. The issues of the supplemental support in pediatric ophthalmology are especially important, as today formation of the visual organ in children develops under increased visual stress. For the total population, including children, of the industrialized countries the most typical form of vitamin deficiency is subnormal vitamin supply, which occurs among almost healthy children of different ages. The supplemental support issues should be considered in relation to certain types of ocular pathology in children. The most common problem today among children is myopia with projected high increase of this refraction anomaly magnitude in the future. The oxidative stress is the main pathogenesis factor of many degenerative diseases development, including myopia. It is considered as the oxidative stress is realized due to both endogenous processes and various external factors impact, including ultraviolet radiation. Not only vitamins with antioxidant properties (A, C, E), but the trace elements (zinc and copper), bioflavonoids (anthocyanoides) and xanthophilic pigments (lutein, zeaxanthin) are necessary to stabilize myopia and to prevent the development of degenerative diseases in adulthood. These substances are involved in the most important physiological and biosynthetic processes in the sclera, retina and other eye structures and render an influence on its microvessels and hemodynamics in general. All these substances are not synthesized in the human body, and in order to maintain metabolism and homeostasis the sufficient alimentary intake should be provided beginning with early age. The complex drugs, which include multipotential and synergistic active substances, are of particular interest.