Research Interests: Psychology and Refraction
Highly detailed colour coded maps are used in the sport of orienteering to enable competitors to navigate from one check point to another and to provide guidance on the nature of the terrain to be traversed. The colours are defined by the... more
Highly detailed colour coded maps are used in the sport of orienteering to enable competitors to navigate from one check point to another and to provide guidance on the nature of the terrain to be traversed. The colours are defined by the International Orienteering Foundation (IOF) and are said to have been chosen so they will not be confused by competitors who have abnormal colour vision. However, there are anecdotal reports that individuals with colour vision defects do have problems with the colour coding. A Minolta Spectrophotometer CM-503i was used to measure the CIE x,y chromaticity co-ordinates and the reflectances of the standard colours recommended by the IOF for the colour coding of orienteering maps, as well as the colours on two maps used in orienteering events. Four pairs of IOF standard colours are likely to be confused by protan observers and four pairs by deutan observers. There were three pairs of colours likely to be confused by both deutan and protan observers on one of the competition maps and one pair likely to be confused by protan observers on the other map. Some of the colours on the actual competition maps differed noticeably from the standard IOF colours. Orienteers with more severe forms of abnormal colour vision are likely to be disadvantaged by their inability to differentiate some colours used on orienteering maps. The IOF should choose different colours that are less likely to be confused or should employ a redundant code (such as a pattern or texture). There is need for better quality control of the colours of competition maps to ensure they do conform to the IOF standard colours.
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<b>Copyright information:</b>Taken from "Little evidence for an epidemic of myopia in Australian primary school children over the last 30 years"BMC Ophthalmology 2005;5():1-1.Published online 11 Feb... more
<b>Copyright information:</b>Taken from "Little evidence for an epidemic of myopia in Australian primary school children over the last 30 years"BMC Ophthalmology 2005;5():1-1.Published online 11 Feb 2005PMCID:PMC552307.Copyright © 2005 Junghans and Crewther; licensee BioMed Central Ltd.50 D spherical equivalence (blue line) or more minus than -0.25DS spherical equivalence (orange line), and, the percentage of Taiwanese children seen in the year 2000 more minus than -0.25D (aqua dashed line) taken from Lin et al, Ann Acad Med 2004 33:27–33.
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<b>Copyright information:</b>Taken from "A role for aquaporin-4 during induction of form deprivation myopia in chick"Molecular Vision 2008;14():298-307.Published online 08 Feb 2008PMCID:PMC2254964. Confocal... more
<b>Copyright information:</b>Taken from "A role for aquaporin-4 during induction of form deprivation myopia in chick"Molecular Vision 2008;14():298-307.Published online 08 Feb 2008PMCID:PMC2254964. Confocal micrograph (40X magnification) with red AQP4 immunolabeling (to the right) of a transverse section of a normal chick retina merged (in middle) with the accompanying differential interference contrast image (to the left) is shown. The layers of the retina are indicated: NFL nerve fiber layer, GC ganglion cell layer, IPL inner plexiform layer, INL inner nuclear layer, IS inner segments of photoreceptors, OS outer segments of photoreceptors, RPE retinal pigment epithelium. It can be seen that labeling is most intense within the NFL, GC and IPL layers. Only very weak label is visible in the INL and photoreceptor region. : Negative control with the primary antibody omitted indicates very weak red non-specific labeling (to the right) merged with the accompanying differential interference contrast image (to the left). : Tissue pre-incubated with purified peptide before AQP4 labeling is shown indicating that blocking of AQP4 sites with the purified peptide successfully prevents binding of the introduced AQP4 antibodies and apparent red immunolabel. Bars=50 μm.
References 1. Ruff R PS. Gender and Age-specific changes in Motor speed and Eye-hand coordination in adults: Normative values for the Finger tapping and Grooved Pegboard tests Perceptual and motor skills 1993; 76: 1219-1230. 2. Vesia M... more
References 1. Ruff R PS. Gender and Age-specific changes in Motor speed and Eye-hand coordination in adults: Normative values for the Finger tapping and Grooved Pegboard tests Perceptual and motor skills 1993; 76: 1219-1230. 2. Vesia M EJ, Prime S, Klavora P. Correlations of selected psychomotor and visuomotor tests with initial Dynavision performance. Perceptual and motor skills 2008; 107: 14-20 3. Lee K, Junghans BM, Ryan M, Khuu S, Suttle CM. Development of a novel approach to the assessment of eye-hand coordination. Journal of neuroscience methods 2014; 228: 50-56. 4. Van Halewyck F, Lavrysen A, Levin O, Boisgontier MP, Elliott D, Helsen WF. Both age and physical activity level impact on eye-hand coordination. Human movement science 2014; 36: 80-96. 5. Suttle CM, Melmoth DR, Finlay AL, Sloper JJ, Grant S. Eye-hand coordination skills in children with and without amblyopia. Invest Ophthalmol Vis Sci 2011; 52: 1851-1864.
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Research Interests: Psychology and Audiology
Research Interests: Psychology and Cognition
<b>Copyright information:</b>Taken from "Little evidence for an epidemic of myopia in Australian primary school children over the last 30 years"BMC Ophthalmology 2005;5():1-1.Published online 11 Feb... more
<b>Copyright information:</b>Taken from "Little evidence for an epidemic of myopia in Australian primary school children over the last 30 years"BMC Ophthalmology 2005;5():1-1.Published online 11 Feb 2005PMCID:PMC552307.Copyright © 2005 Junghans and Crewther; licensee BioMed Central Ltd. Error bars represent standard error.
<b>Copyright information:</b>Taken from "Little evidence for an epidemic of myopia in Australian primary school children over the last 30 years"BMC Ophthalmology 2005;5():1-1.Published online 11 Feb... more
<b>Copyright information:</b>Taken from "Little evidence for an epidemic of myopia in Australian primary school children over the last 30 years"BMC Ophthalmology 2005;5():1-1.Published online 11 Feb 2005PMCID:PMC552307.Copyright © 2005 Junghans and Crewther; licensee BioMed Central Ltd. Error bars represent standard error.
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<b>Copyright information:</b>Taken from "A role for aquaporin-4 during induction of form deprivation myopia in chick"Molecular Vision 2008;14():298-307.Published online 08 Feb 2008PMCID:PMC2254964. A confocal... more
<b>Copyright information:</b>Taken from "A role for aquaporin-4 during induction of form deprivation myopia in chick"Molecular Vision 2008;14():298-307.Published online 08 Feb 2008PMCID:PMC2254964. A confocal micrograph of a transverse section of the retina from a form-deprived eye after 72 h of occluder wear is shown. There is strong labeling in the nerve fiber layer (NFL), ganglion cell (GC) layer, and inner plexiform layer (IPL) but very weak labeling in the inner nuclear layer (INL). Note the branching brush-like appearance of the pattern of AQP4 expression and also the appearance of several sublaminae in the IPL, which is similar to the previously described morphology of the Müller cell []. Bar is 20 µm.
Analysis of elements present in fluids contained in small, poorly accessible sections of biological tissue is challenging. The choroid of the eye, which is a vascular tissue approximately 100 microm thick, surrounds the retina for the... more
Analysis of elements present in fluids contained in small, poorly accessible sections of biological tissue is challenging. The choroid of the eye, which is a vascular tissue approximately 100 microm thick, surrounds the retina for the purposes of nutrient supply and metabolite removal, and which in the chick shows dramatic volumetric change in response to visual experiences. Because fluid homeostasis is critical to good vision, a complete understanding of the ionic changes driving large shifts in ocular fluids is required. However, the structure of the choroid and retina make extraction of pure fluids for analysis extremely difficult. Elemental x-ray analysis on a transverse chorioretinal specimen was performed after rapid freezing of a whole chick eye in liquid nitrogen, and mechanically fracturing the frozen globe. Using a Polaron Cryotrans System on a Cambridge S-360 scanning electron microscope and a Kevex Quantum detector, spectra were obtained for blood vessels, lymphatic vessels and vitreous that were readily visible at 265x. Analysis was performed on a frozen control solution of the elements found in the vessels. The elements and their concentrations found in blood vessels by x-ray analysis compared well with those from whole blood as established by conventional means. The analysis for lymph yielded results compatible with expectations; no other published data for small lymphatics enable a direct comparison. In conclusion, x-ray analysis can be used to acquire information that is otherwise unobtainable from tissue in situ. The same bulk-frozen elemental microanalysis protocol would have application to other organs and tissues when access to the site would destroy the integrity of the tissue under investigation.
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Parent Questionnaire. The questionnaire is to be completed by a parent or guardian of each child participating in the school-based vision screening, and covers the time of the child's last vision assessment and whether there are any... more
Parent Questionnaire. The questionnaire is to be completed by a parent or guardian of each child participating in the school-based vision screening, and covers the time of the child's last vision assessment and whether there are any concerns or other comments about the child's eyes and vision. (DOCX 66 kb)
This project aimed at a definition of pedagogically sound future directions for enhancing the student experience relating to delivering optometric graduates who are prepared and keen to work in the rural sector, and/or with low vision... more
This project aimed at a definition of pedagogically sound future directions for enhancing the student experience relating to delivering optometric graduates who are prepared and keen to work in the rural sector, and/or with low vision patients. A consortium of optometric educators from all schools of optometry in Australia and New Zealand undertook the following activities: (1) conducted worldwide benchmarking across a range of health care disciplines of current pedagogical practice in preparing students for work in rural areas and with special populations; (2) sought input from the profession regarding the optometric needs of the rural and special population sector and the potential role and requirements of optometrists in practice acting as preceptors; and (3) produced a Compendium of Learning Activities and a 'Future directions' statement reflecting educational best practice. The lead institution was the University of New South Wales, partnered by Queensland University of...
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Purpose: The aim was to determine whether the fractal dimension (FD) can differentiate between visual evoked potentials (VEPs) recorded from amblyopic and non-amblyopic visual systems. Methods: Participants were currently amblyopic adults... more
Purpose: The aim was to determine whether the fractal dimension (FD) can differentiate between visual evoked potentials (VEPs) recorded from amblyopic and non-amblyopic visual systems. Methods: Participants were currently amblyopic adults (n = 3), five adults and one child who have recovered from amblyopia and currently have normal vision and adults with normal vision and no history of amblyopia (n = 4). Monocular and binocular VEPs in response to chromatic (isoluminant magenta-cyan) and achromatic sine wave gratings presented pattern onset offset were recorded (active electrode Oz, reference Cz and earth Fz). The stimulus levels were zero contrast, one cycle per degree psychophysical threshold chromatic contrast, one cycle per degree, 42 per cent chromatic contrast and two cycles per degree achromatic gratings. The method of Grassberger and Procaccia’s algorithm and surrogate data sets (Theiler) was used to estimate the fractal dimension for each VEP. Results: The fractal dimension of VEPs from currently amblyopic eyes were significantly higher than from eyes which had recovered from amblyopia and from eyes which were never amblyopic for the zero contrast stimuli (p < 0.028), threshold chromatic contrast stimuli (p < 0.039) and the two cycles per degree achromatic grating stimuli (p < 0.025). ABSTRACTS
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Background To date there have been few systematic attempts to establish the general prevalence of asthenopia in unselected populations of school-aged children. Thus, the aim of this study was to determine whether the incorporation of... more
Background To date there have been few systematic attempts to establish the general prevalence of asthenopia in unselected populations of school-aged children. Thus, the aim of this study was to determine whether the incorporation of Borsting et al’s 2003 Revised Convergence-Insufficiency Symptom Survey (CISS) into a general school vision screening could aid in the identification of children with visual discomfort and indicate the need for further investigation. Methods Vision screening of an unselected middle school population investigated and analysed the incidence of self-reported nearwork-related visual discomfort via the CISS along with distance and near visual acuities plus non-cycloplegic autorefraction using a Shin-Nippon NVision-K 5001. Results Of the 384 unselected students approached in Grades 6–9, 353 participated (92.2%, mean 13.2 ± 1.4 years). The mean CISS score for the population without amblyopia and/or strabismus (96.0% of all students) was 16.8 ± 0.6, i.e., 45% of...
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The use of patient simulators in ophthalmic education appears limited. This study examines the effects of the addition of the 'Virtual Refractor' patient simulator learning activity into a short unit preparing students to... more
The use of patient simulators in ophthalmic education appears limited. This study examines the effects of the addition of the 'Virtual Refractor' patient simulator learning activity into a short unit preparing students to determine the power of the spectacle lenses required by patients in a clinic. Twenty-four year one optometry students were randomly assigned to either the simulator-intervention group (n = 12) or the non-intervention group. All students attended tutorials on refraction and the use of a refractor-head. Simulator-intervention students additionally attended a tutorial on the Virtual Refractor. All answered a questionnaire concerning time spent studying, perceived knowledge and confidence. Twenty-four short-sighted patients were recruited. Two refractions per student were timed and the accuracy compared with that of an experienced optometrist. Ten students from each group completed the study. Students who used the simulator were significantly (p < 0.05) more...
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In many countries, access to general health and eye care is related to an individual's socioeconomic status (SES). We aimed to examine the prevalence of oculo-visual disorders in children in Istanbul Turkey, drawn from schools at SES... more
In many countries, access to general health and eye care is related to an individual's socioeconomic status (SES). We aimed to examine the prevalence of oculo-visual disorders in children in Istanbul Turkey, drawn from schools at SES extremes but geographically nearby. Three school-based vision screenings (presenting distance visual acuity, cover test, eye assessment history, colour vision, gross stereopsis and non-cycloplegic autorefraction) were conducted on 81% of a potential 1014 primary-school children aged 4-10 years from two private (high SES) schools and a nearby government (low SES) school in central Istanbul. Prevalence of refractive errors and school-based differences were analysed using parametric statistics (ANOVA). The remaining oculo-visual aspects were compared using non-parametric tests. Of the 823 children with mean age 6.7 ± 2.2 years, approximately 10% were referred for a full eye examination (8.2% and 16.3% of private/government schools respectively). Vision...
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The choroid of the chick swells markedly during recovery from experimentally induced myopia. It has been demonstrated previously that the lymphatic sinusoids of the choroid contribute most to the expansion. This raises important questions... more
The choroid of the chick swells markedly during recovery from experimentally induced myopia. It has been demonstrated previously that the lymphatic sinusoids of the choroid contribute most to the expansion. This raises important questions about the particular ultrastructural changes occurring in choroidal lymphatics as a means of understanding the role these vessels might play in emmetropization. Thirteen hatchling chicks were monocularly occluded for 2 weeks to induce myopia and then allowed normal visual experiences during recovery for periods of 0 to 72 h before sacrifice. Electron microscopic analysis detailed the temporal progression of vascular changes and provides qualitative evidence for edema in the extravascular space. Quantitative analysis showed that the frequency of open junctions between lymphatic endothelial cells (an indicator of passive fluid transfer) increased over the 3 days of recovery. Lymphatic fenestrations (an indicator of active fluid transfer) were rare in both nondeprived eyes and in form-deprived eyes at the time of occluder removal, but increased in density significantly over the first 24 h of recovery before returning to control levels by 72 h. The number of lymphatic endothelial caveolae did not change significantly during recovery, nor did the number of fenestrations along the walls of choriocapillaris vessels. The walls of the lymphatics of the chick choroid open to allow greater fluid transfer during re-emmetropization than normal; the lymphatics may play an important role in the maintenance of chorioretinal fluid balance and homeostasis.
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Research Interests: Cognitive Science, Computer Aided Design, Humans, Child, Female, and 15 moreMale, Young Adult, Eye Movements, Alkaloids, Adult, Objective, Repeatability, Time Factors, Hand, Age Factors, Hand Eye Coordination, Statistical Methods for Neuroscience, Neurosciences, Psychomotor Performance, and Neuroscience Methods
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Spatial co-localization of aquaporin water channels (AQP4) and inwardly rectifying potassium ion channels (Kir4.1) on the endfeet regions of glial cells has been suggested as the basis of functionally interrelated mechanisms of... more
Spatial co-localization of aquaporin water channels (AQP4) and inwardly rectifying potassium ion channels (Kir4.1) on the endfeet regions of glial cells has been suggested as the basis of functionally interrelated mechanisms of osmoregulation in brain edema. The aim of this study was to investigate the spatial and temporal changes in the expression of AQP4 and Kir4.1 channels in an avascular retina during the first week of the optical induction of refractive errors. Three-day-old hatchling chicks were randomly assigned to three groups and either did not wear lenses or were monocularly goggled with +/-10D lenses for varying times up to 7 days before biometric assessment. Retinal tissue was prepared either for western blot analysis to show the presence of the AQP4 and Kir4.1 protein in the chick retina or for immunolocalization using AQP4 and Kir4.1 antibodies to determine the regional distribution and intensity of labeling during the induction of refractive errors. As expected, ultra...