Yes / To determine the test-retest reproducibility of accommodative facility (AF) measures in an unselected sample of UK primary school children. Methods: Using 2.00 DS flippers and a viewing distance of 40 cm, AF was measured in 136 children (range 4–12 years, average 8.1 2.1) by five testers on three occasions (average interval between successive tests: eight days, range 1–21 days). On each occasion, AF was measured monocularly and binocularly, for two minutes. Full datasets were obtained in 111 children (81.6 per cent). Results: Intra-individual variation in AF was large (standard deviation [SD] = 3.8 cycles per minute [cpm]) and there was variation due to the identity of the tester (SD = 1.6 cpm). On average, AF was greater: (i) in monocular compared to binocular testing (by 1.4 cpm, p < 0.001); (ii) in the second minute of testing compared to the first (by 1.3 cpm, p < 0.001);(iii) in older compared to younger children (for example, AF for 4/5-year-olds was 3.3 cpm lower than in children ≥10 years old, p = 0.009); and (iv) on subsequent testing occasions (for example, visit-2 AF was 2.0 cpm higher than visit-1 AF, p < 0.001). After the first minute of testing at visit-1, only 36.9 per cent of children exceeded published normative values for AF (≥11 cpm monocularly and≥8 cpm binocularly), but this rose to 83.8 per cent after the third test. Using less stringent pass criteria (≥6 cpm monocularly and≥3 cpm binocularly), the equivalent figures were 82.9 and 96.4 per cent, respectively. Reduced AF did not co-exist with abnormal near point of accommodation or reduced visual acuity. Conclusions: The results reveal considerable intra-individual variability in raw AF measures in children. When the results are considered as pass/fail, children who initially exhibit normal AF continued to do so on repeat testing. Conversely, the vast majority of children with initially reduced AF exhibit normal performance on repeat testing. Using established pass/fail criteria, the prevalence of persistently reduced AF in this sample is 3.6 per cent. / UK College of Optometrists

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Accommodation is the change in the dioptric power of the eye altering the focus from distance to near. Presbyopia is the loss of accommodative function that occurs with age. There are many techniques used to measure accommodation, however, there is little consensus as to how clinical data should be collected and analysed. The overarching theme of this thesis is the in vivo examination of accommodation and how lifestyle can affect the onset of presbyopia. An open-field autorefractor with badal adaption was used to examine accommodative dynamic profiles under varying demands of vergence. From this data a new metric for assessing the time for accommodative change was derived. Furthermore this thesis describes a bespoke automated accommodative facility instrument that was developed to provide further assessment of accommodative speeds. Defocus curves are used for assessing accommodation and depth-of-focus; the work presented explores the use of non-linear regression models to define the most appropriate method of assessing defocus curves in phakic subjects, and pseudophakic subjects implanted with an extended depth-of-focus intraocular lens. Using an absolute cut-off criteria of +0.30logMAR improved the repeatability and reliability of the depth-of-focus metrics over a cut-off criteria relative to the best corrected visual acuity. A swept-source anterior segment optical coherence tomographer (AS-OCT) was used to image the morphology of the ciliary muscle during accommodation. The accuracy of ciliary muscle measurements was improved when using reference points on the sclera to align the AS-OCT scan. The use of a ciliary muscle area metric demonstrated poor repeatability and reliability when compared to the traditional assessment of muscle morphology via thickness measurements. Physiological ageing in the crystalline lens occurs in line with ageing in other structures in the body. The methods for assessing accommodative function examined in previous chapters, were used to examine whether lifestyle factors which affect the rate of systemic ageing, such as smoking, also affect accommodative function. Although being a current smoker and having greater central adiposity was associated with a slower time for accommodative change, further research is required before these findings can be applied to the target population.

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Accommodative microfluctuations (AMFs) are temporal variations in the accommodative response. AMFs can be divided into two categories, the low frequency component (LFC) measuring below 0.6 Hz and the high frequency component (HFC) measuring between 1.0 and 2.3 Hz. This thesis examined occupational factors that may affect AMFs comprising of cognitive demand, visual fatigue and the type of digital display used. These effects were measured by assessing changes in the LFC, mid frequency component (MFC), HFC, and RMS accommodation. Analysis of chaos and the overall accommodative response (AR) was also used. Furthermore, an investigation into inter- and intra-participant variability was completed. The HFC was shown to increase in line with increasing cognitive demand. A significant effect for task duration was found at higher accommodative demands for the overall AR, LFC and MFC. There was a significant effect on the LFC and AR depending on the type of display used during near work. The HFC and MFC were found to be less repeatable in the same participant relative to LFC, RMS accommodation and AR measurements. AMFs appear to have an effect on occupational factors, however more research is required to assess how much of an effect they may have relative to other ocular factors that affect occupational settings.

Yes / Background: Soft contact lenses have been developed and licensed for reducing myopia progression. These lenses have different designs, such as extended depth of focus (EDOF) and dual focus (DF). In this prospective, doublemasked, cross-over study, different lens designs were investigated to see whether these had impact on accommodative microfluctuations and eye movements during reading. Methods: Participants were fitted with three lenses in a randomised order; a single vision (SV) design (Omafilcon A2; Proclear), a DF design (Omafilcon A2; MiSight), and an EDOF lens design (Etafilcon A; NaturalVue),. Accommodative microfluctuations were measured at 25 cm for at least 60s in each lens, using a Shin-Nippon SRW-5000 autorefractor adapted to continuously record accommodation at 22Hz. Eye movement data was collected with the Thomson Clinical Eye Tracker incorporating a Tobii Eye bar. Eye movements include fixations per row, fixations per minute, mean regressions per row, total number of regressions, and total rightward saccades. Accommodation data was analysed using power spectrum analysis. Differences between the lenses were compared using a related sample two-way Friedman test. Results: Twenty-three participants (18–29 years) were recruited to take part. The average mean spherical error was − 2.65D ± 1.42DS, with an average age of 23.4 ± 3.5 years. No significant difference for accommodative microfluctuations was found. Significant differences were found for fixations per row (P = 0.03), fixations per minute (P = 0.008), mean regressions per row (P = 0.002), and total number of regressions (P = 0.002), but not total rightward saccades (P = 0.10). Post-hoc analysis indicated the EDOF lens results were significantly different from the other lenses, with more regressive eye movements observed. Conclusions: Regressive saccades appear to increase when wearing EDOF lens designs, which may impact visual comfort. Further studies in children, over a longer period of adaptation are necessary to assess the potential impact of this finding on daily reading activities in children. / This project was supported by the British Contact Lens Association Summer Studentship Award (recipient Muskaan Hussain).

The Thesis deals with freedom and rights of employees in the Canadian province of Québec. The first part characterizes the law in Québec and specifies the system of law in this province. The second part concerns the discrimination and the guarantee of rights and freedom. The topics of the third part are accommodative remedy, its future development, the relation with the increasing number of immigrants and some obstructions that the accommodation has to face sometimes. At the same time, it offers some propositions to accommodate effectively in order to maintain the development and prosperity of a corporation. The Thesis goes along with case studies that illustrate the problems with particular examples from reality.