Search results for "ACCOMMODATION"
showing 10 items of 123 documents
Changes in the objective amplitude of accommodation with pupil size.
2014
PURPOSE We evaluate the effect of pupil size on objectively measured amplitude of accommodation (AA). METHODS Pupil diameter and wavefront aberrometry were obtained in 15 eyes when stimulus swept across the range of clear vision in steps of 0.5 diopters. Wavefront refraction techniques were used to compute objective AA as the maximum refractive change. Measurements were obtained monocularly under low and high ambient room lighting conditions with a fixed luminance of the fixation target. Amplitude of accommodation computations were performed taking into account just paraxial rays (paraxial AA) or including the effects of the change of spherical aberration during accommodation (minRMS AA). R…
Archetypal analysis: contributions for estimating boundary cases in multivariate accommodation problem
2013
[EN] The use of archetypal analysis is proposed in order to determine a set of representative cases that entail a certain percentage of the population, in the accommodation problem. A well-known anthropometric database has been used in order to compare our methodology with the common used PCA-approach, showing the advantages of our methodology: the level of accommodation is reached unlike the PCA approach, no more adjustments are necessary, the user can decide the number of archetypes to consider or leave the selection by a criterion. Unlike PCA, the objective of the archetypal analysis is obtaining extreme individuals, so it is the appropriate statistical technique for solving this type of…
Effect of even and odd-order aberrations on the accommodation response
2017
Aim To investigate the potential effect that odd and even-order monochromatic aberrations may have on the accommodation response of the human eye. Methods Eight healthy subjects with astigmatism below 1 D, best corrected visual acuity 20/20 or better and normal findings in an ophthalmic examination were enrolled. An adaptive optics system was used in order to measure the accommodation response of the subjects' eyes under different conditions: with the natural aberrations being present, and with the odd and even-order aberrations being corrected. Three measurements of accommodation response were monocularly acquired at accommodation demands ranging from 0 to 4 D (0.5 D step). Results The acc…
Focusing in Depth: Post-Task Accommodation Shifts After Sustained Near Work with Volumetric Multi-Planar Display
2018
Post-task refraction shifts were evaluated with eccentric photorefraction technique to better understand response of visual system and eye accommodation to sustained near work with 3D image formed by volumetric display.
Redzes treniņu iedarbība uz tuvuma redzes uzdevumiem
2017
Bakalaura darbs “Redzes treniņu iedarība uz tuvuma redzes uzdevumiem” ir uzrakstīts angļu valodā uz 34 lapām. Tas satur 17 attēlus un 32 atsauces uz literatūras avotiem. MĒRĶIS: Šī pētījuma mērķis ir novērtēt redzes treniņu efektivitāti cilvēkiem, kuri sūdzas par tuvuma slodzes radītu redzes stresu. METODE: Pētījums tika veikts Itālijā 23 cilvēkiem ar tuvredzību - biroja darbiniekiem, vecumā no 25 līdz 35 gadiem (15 sievietēm un 8 vīriešiem). Treniņu ilgums bija 3 mēneši un tas ietvēra virkni vingrinājumu akomodācijas elstībai un sakāžu skaita uzlabošanai. SECINĀJUMI: redzes asums, kā arī akomodācijas/verģences sistēmas darbība būtiski uzlabojās pēc redzes treniņiem. ATSLĒGVĀRDS: akomodācij…
Il palazzo di Phestos a Creta: Scavo e restauro
2014
Nel 1900, la Missione Archeologica Italiana di Creta, guidata da Federico Halbherr, con la collaborazione di alcuni archeologi e studenti di archeologia, fra i quali Luigi Pernier, scoprì i resti del palazzo minoico di Festòs, posto a pochi chilometri da Eraklion, capoluogo dell’isola di Creta. Contemporaneamente alla messa in luce dei resti furono eseguiti i primi interventi di restauro e sistemazione, tra questi la pulitura degli interstizi fra i conci lapidei e la stesura di malta cementizia colorata, in modo da intonarla rispetto ai resti, la sistemazione delle parti superiori dei resti murari e la costruzione dei solai in calcestruzzo di cemento armato, un tempo realizzati con struttur…
Touristification, Sharing Economies and the New Geography of Urban Conflicts
2018
The aim of this study was to address the highly controversial problem of the increasing touristification of urban centers, analyzing the case of Valencia. The paper begins with a theoretical reflection to disambiguate the term &ldquo
An examination of the impact of care giving styles (accommodation and skilful communication and support) on the one year outcome of adolescent anorex…
2016
Abstract Background The cognitive interpersonal model predicts that parental caregiving style will impact on the rate of improvement of anorexia nervosa symptoms. The study aims to examine whether the absolute levels and the relative congruence between mothers' and fathers' care giving styles influenced the rate of change of their children's symptoms of anorexia nervosa over 12 months. Methods Triads ( n =54) consisting of patients with anorexia nervosa and both of their parents were included in the study. Caregivers completed the Caregiver Skills scale and the Accommodation and Enabling Scale at intake. Patients completed the Short Evaluation of Eating Disorders at intake and at monthly in…
Are near visual signs and symptoms in multiple sclerosis compatible with convergence insufficiency?
2021
Clinical relevance: Optometric management of neurodegenerative diseases is essential since visual signs, such as double vision, visual acuity reduction, or oculomotricity dysfunctions, are usually present in these subjects over the course of the disease. The present paper can guide clinicians in better managing their patients with multiple sclerosis. Background: Patients with multiple sclerosis present near vision symptoms that may be related to binocular anomalies, but these symptoms have not been investigated and related to specific signs. The aim of the present study was to evaluate the binocular vision in subjects with multiple sclerosis, and to analyse if the near visual signs and symp…
Impact of internal curvature gradient on the power and accommodation of the crystalline lens
2017
Human crystalline lens has a layered, shell-like structure with the refractive index increasing from cortex to nucleus (gradient index or GRIN structure). Moreover, every iso-indicial layer has a certain curvature which also varies from cortex to nucleus, with a gradient of curvature (G). In the present manuscript, the role of G on the lens power is investigated along with its implications regarding the lens paradox (change of lens power with age) and intra-capsular accommodation mechanism (larger than expected changes of lens power during accommodation compared to a homogenous lens). To this end, a simplified formulation of paraxial lens power based on thin lens approximation is developed …