Letter to the Editor: Authors' response.

yesWe thank Professors Evans and Wilkins for their interest in our systematic review.(1) We have reached the same conclusion as previous systematic reviews published in 2008(2) and 2014(3) and a review prepared for the New Zealand Ministry for Health in 2009.(4) Even the ‘alternative systematic review’ prepared by Professors Evans and Allen about which we have significant misgivings concludes that ‘larger and rigorous randomised controlled trials of interventions for visual stress are required’.(5)A response to Professors Evans and Wilkins regarding the systematic review: Griffiths PG, Taylor RH, Henderson LM and Barrett BT (2016) The effect of coloured overlays and lenses on reading: a systematic review of the literature. Ophthalmic & Physiological Optics. 36: 519–544

Coloured overlays and precision-tinted lenses: poor repeatability in a sample of adults diagnosed with visual stress

Purpose Visual stress consists of perceived distortions or discomfort while reading. It is claimed that these symptoms are alleviated by viewing through coloured lenses or overlays, with a specific colour required for each individual. This has been explained on the basis of altered visual cortex excitation as affected by the spectral content of the viewing light. If symptoms are indeed alleviated by a particular colour that has an impact on the individual's visual system, we would expect that selection of the most beneficial colour would be repeatable. The aim of this study was to determine whether this is the case. Methods Twenty-one participants (mean age 26 years (range 8–55 years); 12 female, nine male) with visual stress and no other uncorrected ocular or visual anomaly were recruited. Each participant selected the colour most beneficial in alleviating their symptoms from a standard set of 10 coloured overlays, and underwent intuitive colorimetry in which the most beneficial of a wide range of chromatic illuminance settings was selected. Without prescribing an overlay at the first appointment, this process was repeated on a second occasion at a mean of 25 days later. Results About half of the participants (n = 10) chose the same (n = 7) or similar (with one common colour in both choices; n = 3) coloured overlay on the two occasions, while 11 participants chose a completely different overlay colour. Across all participants, the colorimetry setting shifted by, on average, 9.6 just noticeable differences, indicating that the colours were perceptually very different. Conclusion These findings suggest that people with visual stress are unlikely to find exactly the same colour to be optimal on different occasions, and raise questions about the need for precise colour specification in tinted lenses for visual stress

Using coloured filters to reduce the symptoms of visual stress in children with reading delay

Background: Meares Irlen Syndrome (MIS), otherwise known as “visual stress”, is one condition that can cause difficulties with reading. Aim: This study aimed to compare the effect of two coloured-filter systems on the symptoms of visual stress in children with reading delay. Methods: The study design was a pre-test, post-test, randomized head-to-head comparison of two filter systems on the symptoms of visual stress in school children. A total of 68 UK mainstream schoolchildren with significant impairment in reading ability completed the study. Results: The filter systems appeared to have a large effect on the reported symptoms between pre and post three-month time points (d = 2.5, r = 0.78). Both filter types appeared to have large effects (Harris d = 1.79, r = 0.69 and DRT d = 3.22, r = 0.85). Importantly, 35% of participants’ reported that their symptoms had resolved completely; 72% of the 68 children appeared to gain improvements in three or more visual stress symptoms. Conclusion and significance: The reduction in symptoms, which appeared to be brought about by the use of coloured filters, eased the visual discomfort experienced by these children when reading. This type of intervention therefore has the potential to facilitate occupational engagement

Coloured overlays and precision-tinted lenses: poor repeatability in a sample of adults diagnosed with visual stress (vol 37, pg 542, 2017)

Purpose Visual stress consists of perceived distortions or discomfort while reading. It is claimed that these symptoms are alleviated by viewing through coloured lenses or overlays, with a specific colour required for each individual. This has been explained on the basis of altered visual cortex excitation as affected by the spectral content of the viewing light. If symptoms are indeed alleviated by a particular colour that has an impact on the individual's visual system, we would expect that selection of the most beneficial colour would be repeatable. The aim of this study was to determine whether this is the case. Methods Twenty-one participants (mean age 26 years (range 8–55 years); 12 female, nine male) with visual stress and no other uncorrected ocular or visual anomaly were recruited. Each participant selected the colour most beneficial in alleviating their symptoms from a standard set of 10 coloured overlays, and underwent intuitive colorimetry in which the most beneficial of a wide range of chromatic illuminance settings was selected. Without prescribing an overlay at the first appointment, this process was repeated on a second occasion at a mean of 25 days later. Results About half of the participants (n = 10) chose the same (n = 7) or similar (with one common colour in both choices; n = 3) coloured overlay on the two occasions, while 11 participants chose a completely different overlay colour. Across all participants, the colorimetry setting shifted by, on average, 9.6 just noticeable differences, indicating that the colours were perceptually very different. Conclusion These findings suggest that people with visual stress are unlikely to find exactly the same colour to be optimal on different occasions, and raise questions about the need for precise colour specification in tinted lenses for visual stress

Visual stress, its treatment with spectral filters, and its relationship to visually induced motion sickness

We review the concept of visual stress and its relation to neurological disease. Visual stress can occur from the observation of images with unnatural spatial structure and an excess of contrast energy at spatial frequencies to which the visual system is generally most sensitive. Visual stress can often be reduced using spectral filters, provided the colour is selected with precision to suit each individual. The use of such filters and their effects on reading speed are reviewed. The filters have been shown to benefit patients with a variety of neurological conditions other than reading difficulty, all associated with an increased risk of seizures. © 2009 Elsevier Ltd

A systematic review of controlled trials on visual stress using Intuitive Overlays or the Intuitive Colorimeter

Claims that coloured filters aid reading date back 200 years and remain controversial. Some claims, for example, that more than 10% of the general population and 50% of people with dyslexia would benefit from coloured filters lack sound evidence and face validity. Publications with such claims typically cite research using methods that have not been described in the scientific literature and lack a sound aetiological framework. Notwithstanding these criticisms, some researchers have used more rigorous selection criteria and methods of prescribing coloured filters that were developed at a UK Medical Research Council unit and which have been fully described in the scientific literature. We review this research and disconfirm many of the more extreme claims surrounding this topic. This literature indicates that a minority subset of dyslexics (circa 20%) may have a condition described as visual stress which most likely results from a hyperexcitability of the visual cortex. Visual stress is characterised by symptoms of visual perceptual distortions, headaches, and eyestrain when viewing repetitive patterns, including lines of text. This review indicates that visual stress is distinct from, although sometimes co-occurs with, dyslexia. Individually prescribed coloured filters have been shown to improve reading performance in people with visual stress, but are unlikely to influence the phonological and memory deficits associated with dyslexia and therefore are not a treatment for dyslexia. This review concludes that larger and rigorous randomised controlled trials of interventions for visual stress are required. Improvements in the diagnosis of the condition are also a priority

Does Gender Influence Colour Choice in the Treatment of Visual Stress?

Purpose Visual Stress (VS) is a condition in which words appear blurred, in motion, or otherwise distorted when reading. Some people diagnosed with VS find that viewing black text on white paper through coloured overlays or precision tinted lenses (PTLs) reduces symptoms attributed to VS. The aim of the present study is to determine whether the choice of colour of overlays or PTLs is influenced by a patient’s gender. Methods Records of all patients attending a VS assessment in two optometry practices between 2009 and 2014 were reviewed retrospectively. Patients who reported a significant and consistent reduction in symptoms with either overlay and or PTL were included in the analysis. Overlays and PTLs were categorized as stereotypical male, female or neutral colours based on gender preferences as described in the literature. Chi-square analysis was carried out to determine whether gender (across all ages or within age groups) was associated with overlay or PTL colour choice. Results 279 patients (133 males and 146 females, mean age 17 years) consistently showed a reduction in symptoms with an overlay and were included. Chi-square analysis revealed no significant association between the colour of overlay chosen and male or female gender (Chi-square 0.788, p = 0.674). 244 patients (120 males and 124 females, mean age 24.5 years) consistently showed a reduction in symptoms with PTLs and were included. Chi-square analysis revealed a significant association between stereotypical male/female/neutral colours of PTLs chosen and male/female gender (Chi-square 6.46, p = 0.040). More males preferred stereotypical male colour PTLs including blue and green while more females preferred stereotypical female colour PTLs including pink and purple. Conclusions For some VS patients, the choice of PTL colour is influenced not only by the alleviation of symptoms but also by other non-visual factors such as gender

Identifying visual stress during a routine eye examination

Purpose: To investigate whether the clinical tests used in routine eye examinations can identify adults whose reading rate increases with their preferred coloured overlay(s). Methods: Routine optometric tests were used to measure 73 undergraduate students’ refractive error, visual acuity, stereo-acuity, amplitude of accommodation, near point of convergence, associated heterophoria at near, colour vision and ocular motility. Participants chose an overlay or combination of overlays with colour optimal for clarity, and completed the Wilkins Rate of Reading Test with and without an overlay(s) of this colour. Results: Overall, there was a significant increase in reading speed with overlay (t(72) = −5.26, p 5% with their chosen coloured overlay(s). Ten participants (14%) had a reading speed increase of >10%. The increase in reading speed was not significantly associated with any clinical finding. Conclusion: Tests which are completed in routine eye examinations did not identify those participants who benefitted from coloured overlays in terms of reading speed

A review of the effects of colour and light on non-image function in humans

This paper reviews current knowledge on non-image-forming aspects of vision. Developments in the last 20 years have included the discovery of a fifth class of human visual pigment (melanopsin), in addition to the three classes of photopsin to be found in the cones and rhodopsin in the rods in the human retina. Melanopsin is found in a small number of retinal ganglion cells which then, in addition to receiving input from rods and cones, are intrinsically photosensitive. These retinal ganglion cells send their input primarily to the hypothalamus, where they help to regulate the circadian system (daily rhythms of sleep patterns, body temperature, heart rate, etc.). The discovery of the anatomical basis of non-image-forming vision has led to a great deal of research into the effects of light on sleep, depression and mood, retinal photodamage and well-being, amongst other factors. Given that recent technological innovations in LED lighting now give us greater control over environmental lighting, it is timely to review the non-visual effects of light in humans in order to inform lighting design in the future

Design of college education evaluation based on accompanying data acquisition and mathematical analysis

According to the needs of higher education teaching evaluation, we analyzes the problems in teaching evaluation, provide the method of using accompanying data acquisition and mathematical analysis, designs the education and teaching big data platform, collects the relevant data generated in the teaching process in real time by using information system, video equipment and IoT system, optimizes the evaluation indicators, and constructs the evaluation model, achieve comprehensive evaluation in objectively and real time