Children with early onset myopia demonstrate greater accommodative variability than emmetropic children, and have similar patterns of response to adult late onset myopes. This increased variability could result in an increase in retinal blur for both near and far targets. The role of accommodative variability in the etiology of myopia is discussed.

Horizontal pursuit eye movements were investigated in two separate groups of children: One group exhibited developmental co-ordination disorder (n = 8) whilst another group of children were born prematurely (n = 8). Both studies found a reduced gain in pursuit eye movements when the respective populations were compared with control groups (n = 32). A difference was also found in the ability of some children to temporally synchronize their tracking response to the stimulus, which was indicative of poor predictive control rather than lags in the control system. We suggest that horizontal eye movements may be a sensitive indicator of more general motor deficits during childhood development.

Background Undetected vision problems is an important cause of reduced academic achievement, performance in everyday life and self-esteem. This receives little attention in national health care services in Norway even though most of these vision problems are easily correctable. There are no published data on how many Norwegian schoolchildren are affected by correctable vision problems . This study aims to determine the vision status in primary and secondary schoolchildren referred from vision screening during the 10 year period of 2003–2013. Methods Of the 1126 children (15%) aged 7–15 years referred to the university eye clinic by the school screening program, all 782 who attended the eye clinic were included in the study. Patient records were retrospectively reviewed with regard to symptoms, refractive error, best corrected visual acuity (BCVA) of logMAR, binocular vision, ocular health and management outcomes. Results Previously undetected vision problems were confirmed in 650 (83%) of the children. The most frequent outcomes were glasses (346) or follow-up (209), but types of treatment modalities varied with age. Mean refractive errors were hyperopic for all age groups but reduced with age (ANOVA, p < 0.001). Overall, 51% were hyperopic, 32% emmetropic and 17% myopic. Refractive errors did not change across the decade (linear regression, all p > 0.05). Mean logMAR BCVAs were better than 0.0 and improved with age (ANOVA, p < 0.001) . The most prevalent symptoms were headaches (171), near vision problems (149) and reduced distance vision (107). Conclusions The vision screening identified children with previously undetected visual problems. This study shows that the types of visual problems varied with age and that most problems could be solved with glasses. Our results stress the importance of regular eye examinations and that vision examinations should be included in primary health care services. Furthermore, there is a need for raised awareness among parents and teaching staff regarding vision problems in children.

Optometric disorders are likely to increase the difficulties experienced by an individual who is struggling to read. There are some reports of a higher incidence of visual abnormalities in children with dyslexia, but there has been little investigation into adults. We therefore investigated the optometric status of a population comprising children and adults with dyslexia. Fifty-four patients (27 with dyslexia, 27 controls) underwent extensive optometric testing. Measurements included visual acuity, cycloplegic refraction, accommodation and binocular vision testing. There was a higher proportion of individuals with dyslexia presenting with optometric problems compared to controls. For children with dyslexia, the most common diagnosis were hypermetropia [far-sightedness] (forty-one percent compared to eighteen percent of the control group) and accommodation insufficiency (thirty-five percent compared to no controls). Untreated optometric disorders were present in both children and adults with dyslexia. The results strongly suggest that an optometric examination should be included in the management of this condition.

Background Lifestyle behaviour in children and adolescents has become increasingly sedentary and occupied with digital work. Concurrently, there has been an increase in the prevalence of headache, neck- and low back pain, which are leading causes of disability globally. Extensive near work and use of digital devices are demanding for both the visual system and the upper body head-stabilizing musculature. Uncorrected vision problems are present in up to 40% of Nordic school children, and a lack of corrective eye wear may cause eyestrain, musculoskeletal pain and headache. The aim of this study was to investigate associations between laboured reading, musculoskeletal pain, uncorrected vision, and lifestyle behaviours in children and adolescents. Methods This was a cross-sectional study with a total of 192 Norwegian school children aged 10–11 and 15–16 years. As a part of a school vision testing program, the children completed an online questionnaire about general and ocular health, socioeconomic status, academic ambition, near work and related symptoms, upper body musculoskeletal pain, and physical and outdoor activities. Results The 15–16-year-olds had a more indoor, sedentary, digital-based lifestyle with higher academic demands, compared with the 10–11-year-olds. Concurrently, reading became more laboured and upper body musculoskeletal pain increased with age. Girls reported more symptoms, higher academic ambitions, and more time spent on schoolwork and reading, compared with boys. Non-compliance in wearing prescribed eye wear (glasses or contact lenses), increased use of near digital devices, and experiencing visual stress (glare) were positively associated with laboured reading and upper body musculoskeletal pain. Conclusions A screen-based lifestyle with high academic demands challenges the ability to sustain long hours of static, intensive near work. Extensive near work tires the visual system and upper body musculature and provokes laboured reading and musculoskeletal pain symptoms. This study emphasizes the importance of regular eye examinations in school children, and the need to raise awareness among children, parents, and school- and health personnel about the importance of optimal vision and visual environment for academic performance and health.

Background:In a previous study, we demonstrated that children with early onset myopia had greater instability of accommodation than a group of emmetropic children. Since that study was correlational, we were unable to determine the causal relationship between this and myopic progression. To address this, we examined the children two years later. We predicted that if accommodative instability was causing the myopic progression, instability at Visit 1 should predict the refractive error at Visit 2. Additionally, instability at Visit 1 should predict myopic progression. Methods: Thirteen myopic and 16 emmetropic children were included in the analysis. Dynamic measures of accommodation were made using eccentric photorefraction (PowerRefractor) while children viewed targets set at three distances (accommodative demands), namely, 0.25 metres (4.00 D demand), 0.5 metres (2.00 D demand) and 4.00 metres (0.25 D demand). Results: Both refractive error and accommodative instability at Visit 1 were highly correlated with the same measures at Visit 2. Children with myopia showed greater instability of accommodation (0.38 D) than children with emmetropia (0.26 D) at the 4.00 D target on Visit 1 and this instability of accommodation weakly predicted myopic progression. Conclusions:The results presented in the present study suggest that instability of accommodation accompanies myopic progression, although a casual relationship cannot be established.

Previous research has explored the development of visual acuity in babies and children, and it has been established that the measured visual acuity is dependent on the method used. In the present study developmental trends in crowded versus single letter visual acuities were explored. 343 children, 5 to 11 years of age, were tested using Glasgow Acuity Cards (GAC), and a significant correlation between binocular visual acuity and age was found using simple regression analysis (y = 0.023x + 0.81, r2 = 0.32). Mean values of crowded visual acuity varied between 0.95 ± 0.06 logMAR in 5-year-olds to 1.08 ± 0.09 logMAR in 11-year-olds. One way ANOVA confirmed the developmental trend [F(1, 341) = 160.45, p < 0.0001]. In a second study, these results were replicated in a smaller group of fully corrected children (regression analysis showed significant development with age, y = 0.025x + 0.86, r2 = 0.429, one way ANOVA: [F(1, 72) = 54.11, p < 0.0001]. The repeatability of the GAC was tested using a test-retest strategy, 6 months apart. A significant improvement of monocular visual acuities at the retest may be explained, at least in part, by the expected development of visual acuity during this period. A single letter acuity test was constructed by matching GAC optotypes. Fifty two emmetropic children (mean age 8.21 ± 1.76 years) were tested on both tests. Developmental trends were then compared for single and crowded acuities. Linear regressions were F(1, 50) = 23.87, p = 0.0001, y = 0.019x + 0.915, r2 = 0.31 for crowded letters and F(1, 50) = 5.81, p < 0.05, y = 0.009x + 1.07, r2 = 0.104 for single letters. Repeated measures ANOVA (test * age) showed reliable differences for both main effects. Single letter acuity was found to display a very slight developmental trend, and was better than crowded acuity. When deciding normal values and cut-off limits, one must take into consideration which test is being used, as normative data will not directly translate from one test to another.

The purpose of this study was to investigate the effect of optically induced refractive errors on saccade latency and fixation stability.Sixteen healthy, young adults (two males), with normal visual acuity and normal accommodation, performed a saccade task and a fixation task wearing a range of contact lenses (from +3.00 to -5.00 diopters) which induced visual blur and accommodation. The results showed that mean (± standard error) saccade latency was 207 (± 5) milliseconds (ms) and remained stable with both visual blur and accommodation, whereas mean (± standard error) fixation stability was logBCEA 2.48 (± 0.03) (arcmin²) and declined by about 0.09 logBCEA with both visual blur and accommodation.  In healthy adults with normal vision, results indicate that recording of saccade latency can be completed accurately regardless of the moderate refractive errors induced in this study. Fixation stability, on the other hand, degrades slightly with blur and with accommodation.