0000000000616444
AUTHOR
Karola Panke
Visual Acuity in Myopes with Standard and Reversed Contrast Optotypes
Abstract The aim of this study was to assess the visual acuity of myopes with standard and reversed contrast optotypes and to determine how the visual acuity of myopes is affected by optical defocus and the type of optical correction, either contact lenses or spectacles. Twenty-three myopic subjects (18 and 23 years old) with uncorrected vision had their visual acuity assessed with both standard and reversed contrast optotypes. The study also included 10 myopes with contact lens as well as habitual spectacle correction. The visual acuity for myopes with uncorrected vision was better with reversed than standard contrast optotypes. Better reversed contrast than standard contrast visual acuity…
Impact of viewing distance on relative depth judgements for stimuli in physical space
In natural viewing, numerous depth cues are available to the visual system, but their significance varies considerably depending on the viewing distance. How is it reflected in the outcome of depth judgements? We have designed a psychophysical experiment with a limited number of depth cues to examine distance-related changes in the correct response rate and time. Twenty young adults evaluated relative depth of stimuli in physical space. Each time four constant angular size achromatic stimuli were presented on a volumetric multi-planar display. One of these stimuli was demonstrated closer to the observer comparing to others. The experiment followed the four-interval forced-choice procedure. …
Changes in physiological astigmatism of human eye during accommodation in emmetropes (Conference Presentation)
Introduction: Most young emmetrope eyes are far from ideal and have some degree of minor spherocylindrical error including also physiological astigmatism. Because of the changes in the shape of optical interfaces, pupil size, eyelid pressure, tear film, body posture, binocularity and accommodation astigmatism is considered as constantly dynamic phenomenon (Cheng et al, 2004). The purpose of this study was to evaluate and quantify changes in physiological astigmatism during accommodation. Method: Twenty young emmetropes with mean age 24 ± 4 years were selected for the study. Refraction and accommodative response were measured monocularly for dominant eye with an open-field infrared autorefract…
Akomodācijas atpalikšanas saistība ar nespecifisku tuvuma darba diskomfortu
Maģistra darbs ir uzrakstīts latviešu valodā, uz 58 lapām. Tas satur 27 attēlus, 7 tabulas, 3 pielikumus un 52 atsauces uz literatūras avotiem. Darba mērķis: novērtēt akomodācijas atpalikšanas un citu redzes funkciju raksturojošo parametru saistību ar nespecifisku tuvuma darba diskomfortu. Metode: Akomodācijas atpalikšana tika mērīta ar Shin–Nippon SRW–5000 atvērta skata autorefraktometru 3 attālumos (40 cm, 30 cm un 34 cm), gan binokulāri, gan monokulāri. Subjektīvo simptomu novērtēšanai tika izmantotas CISS un Conlon aptaujas anketas. Rezultāti un secinājumi: Monokulāros apstākļos akomodācijas atpalikšana un SD ir lielāka kā binokulāros apstākļos, un palielinās, samazinoties darba attālum…
Visual Search Performance Depending on Target-Distractor Difference on Volumetric Display and Flat Panel Display
The search items were demonstrated on the volumetric display and flat panel display. In contrast to the correct response rate, the search time and number of interactions were considerably affected by the type of visualization.
Ocular performance evaluation
Real and virtual three-dimensional (3D) imaging has found useful applications across different areas of health sciences and with the current rapidly progressive development stage we can expect that the use of 3D imaging soon will be a part of a daily visual load for medical personnel. To better understand the possible impact of prolonged work with 3D content on eye accommodative response and pupil size we compared two 3D imaging techniques - volumetric display that is real voxel-based system and anaglyph technique that is virtual pixel-based system. We have investigated accommodative lag and pupil responses in 38 emmetropic young adult after prolonged visual task with volumetric 3D display …
Cilvēka fizioloģijas un uztveres aktuālie pētījumi 2020. gadā
Šajā izdevumā apkopoti LU FMOF Optometrijas un redzes zinātnes nodaļas un tās sadarbības partneru aktuālie pētījumi par cilvēka fizioloģiju un uztveri. 2020. gadā. Pētījumi ir saistīti ar redzes zinātni un klīnisko optometriju. Daļa rakstu ir latviešu, daļa angļu valodā. // This collection of publications consists of research done in Department of Optometry and Vision Science, Faculty of Physics, Mathematics and Optometry, University of Latvia. Reasearch topics are related with vision science and clinical optometry. Some of the articles are in Latvian, some of them are in English.
Cilvēka fizioloģijas un uztveres aktuālie pētījumi 2019.gadā : rakstu krājums
Izdevumā apkopoti LU FMOF Optometrijas un redzes zinātnes nodaļas, kā arī citu struktūrvienību aktuālie pētījumi par cilvēka fizioloģiju un uztveri. 2019. gads Optometrijas un redzes zinātnes nodaļā ir zīmīgs ar nodaļas ilggadējo profesoru jubilejām. Savu apaļo dzimšanas dienu jau ir nosvinējis LU emeritus profesors Ivars Lācis, kurš ir devis lielu ieguldījumu Latvijas Universitātes attīstībā, kā arī viens no Latvijas optometrijas stūrakmeņiem. Šajā izdevumā bez zinātniskiem rakstiem ir īss ieskats viņa biogrāfijā, kura tapusi sadarbībā ar Latvijas Universitātes bibliotēku.
Smartphone viewing distance during active or passive tasks and relation to heterophoria
Our aim was to analyze viewing distance for smartphone users (aged 18-45 y.) in terms of passive or active task, relation to heterophoria, type of refractive error and smartphone font size. Participants were asked to read out loud text message (passive task) and afterwards rewrite the same text and send back (active task). For the text message we used sentence consisting of 23 words and 200 characters (with spaces). Participants used their own smartphones (font size monitored). For both passive and active task we measured task time and viewing distance at the end of the task. We found significantly shorter viewing distance for digital active task compared to passive task (29.3 ± 4.7 and 32.…
Focusing in Depth: Post-Task Accommodation Shifts After Sustained Near Work with Volumetric Multi-Planar Display
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.
Monokulāri ģenerētu aberāciju interokulārā pārnese
Bakalaura darbs ir uzrakstīts latviešu valodā, datorsalikumā uz 57 lapām. Tas satur 46 attēlus, 8 tabulas, 3 pielikumus un 44 atsauces uz literatūras avotiem. Atslēgas vārdi: viļņu frontes aberācijas, adaptīvā optika, akomodācija. Darba mērķis: noskaidrot vai aberācijas izraisa akomodāciju un vai šī akomodācija tiek interokulāri pārnesta, kā arī vai interokulāri pārnestā akomodācija ierosina aberācijas. Metode: Tika izstrādāta adaptīvās optikas iekārta, lai ģenerētu un mērītu viļņu frontes aberācijas. Secinājumi: Monokulāri ģenerēts astigmātisms, trīslapiņa, koma un sfēriskā aberācija ierosina akomodāciju, kas tiek interokulāri pārnesta. Interokulāri pārnestā akomodācija izraisa sfēriskās a…
Acs akomodācijas darbība digitālo tehnoloģiju laikmetā: subjektīvās un objektīvās acs akomodācijas novērtēšanas metodes un normas
Pētījuma pirmā daļa veltīta dabiskas, vecuma izraisītas akomodācijas spēju samazināšanās (presbiopijas) procesa izpētei no klīniskās puses. Tiek kritiski izvērtēts koncepts par vecumam atbilstošām normas vērtībām un, balstoties uz pētījuma rezultātiem, piedāvāts modelis, kas ļauj precīzāk paredzēt indivīda vecumam sagaidāmo tuvuma korekcijas apjomu. Papildu iegūtie rezultāti parāda sakarību starp presbiopijas attīstības pakāpi un korekcijas ietekmi uz tuvuma darbu veiktspēju, kas ļauj prognozēt potenciālo ietekmi uz dzīves kvalitāti cilvēkiem pēc 45 gadu vecuma. Darba otrajā daļā tiek piedāvāta metodoloģija kā papildināt subjektīvos akomodācijas funkciju novērtēšanas testus ar dinamiski ieg…
Looking in Depth: Visual Distance Perception of Stimuli on Volumetric Multi-Planar Display
Ability to distinguish relative location of visual stimuli on a multi-planar display was evaluated within psychophysical experiment in order to figure out the impact of physical distance between stimuli across depth of volumetric data.
Visual search in three-dimensional non-medical images: visual-motor performance of radiologists
The visual search abilities of radiologists are systematically trained due to the specifics of their professional tasks. We investigated whether the visual-motor performance of radiologists, residents and students varied when searching non-medical targets on the volumetric display. As a result, no significant differences were found in the correct response rate among three groups. However, the total number of interactions was considerably higher for the resident radiologists and medical students comparing to the experienced radiologists. Our results suggest that the radiological experience does not interfere with the outcome in the developed visual search task, but may be reflected in motor …
Assessment of spatial perception for a multi-layer volumetric display: the effect of exocentric and egocentric distance on relative depth judgements
Three-dimensional images on multiple depth layers of the volumetric display provide the physiological depth cues which ensure the high precision of depth judgements at close viewing distances and enhance the user experience. However, the contribution of physiological cues declines with an increase of viewing distance (egocentric distance), and the human spatial perception varies depending on the inter-stimuli distance (exocentric distance). We conducted a psychophysical experiment to test the perception of three-dimensional images rendered on the volumetric display depending on exocentric and egocentric stimuli distance. The constant angular size visual stimuli were displayed on different d…
Accommodative Amplitude in School-Age Children
Abstract In children, intensive near-work affects the accommodation system of the eye. Younger children, due to anatomical parameters, read at smaller distance than older children and we can expect that the accommodation system of younger can be affected more than that of older children. We wanted to test this hypothesis. Some authors showed that the norms of amplitude of accommodation (AA) developed by Hofstetter (1950) not always could be applied for children. We also wanted to verify these results. A total of 106 (age 7-15) children participated in the study. Distance visual acuity was measured for all children and only data of children with good visual acuity 1.0 or more (dec. units) we…