Download full-text PDF |
Source |
|---|
Publication Analysis
Top Keywords
Similar Publications
Haidinger's brushes: Psychophysical analysis of an entoptic phenomenon.
Vision Res
October 2022
Department of Physics and Astronomy 'G. Galilei', University of Padova, via Marzolo 8, 35131 Padova, Italy; Padua Quantum Technologies Research Center, University of Padova, via Gradenigo 6, 35127 Padova, Italy. Electronic address:
Entoptic phenomena are visual artifacts arising from the interaction of light with the specific anatomic structure of the human eye. While they are usually too subtle to actually enable additional visual abilities, their perception can provide indirect information on the physiological conditions of the visual system. Among the most famous ones, Haidinger's brushes consist in the appearance of a yellowish bow tie perceived in the presence of linearly polarized white light and originate from the particular spatial distribution of dichroic carotenoid molecules forming a sort of embedded radial polarizer in the foveal region.
View Article and Find Full Text PDFVisual snow syndrome: A clinical and phenotypical description of 1,100 cases.
Neurology
February 2020
From the Headache Group (F.P., P.J.G.), Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology & Neuroscience, King's College London; NIHR-Wellcome Trust King's Clinical Research Facility (F.P., P.J.G.), SLaM Biomedical Research Centre, King's College Hospital, London, UK; and Department of Neurology (C.S.), Inselspital, Bern University Hospital, University of Bern, Switzerland.
Objective: To validate the current criteria of visual snow and to describe its common phenotype using a substantial clinical database.
Methods: We performed a web-based survey of patients with self-assessed visual snow (n = 1,104), with either the complete visual snow syndrome (n = 1,061) or visual snow without the syndrome (n = 43). We also describe a population of patients (n = 70) with possible hallucinogen persisting perception disorder who presented clinically with visual snow syndrome.
Microperimetry - A New Tool for Assessing Retinal Sensitivity in Macular Diseases.
J Clin Diagn Res
July 2017
Senior Statistician, Department of Statistics, Mahatma Gandhi Medical College and Research Institute, Puducherry, India.
Introduction: Macular disease is the leading cause of low vision in the Western world. Drusen and pigmentary irregularities are common among the rural Northern Indian population. The disease process leads to loss of central vision, metamorphopsia, macropsia or micropsia and colour vision defect.
View Article and Find Full Text PDFA thorough analysis of the literature on retinal image stabilization, as well as our own experimental data, present evidence that Yarbus's concept, implying inevitable and irreversible fading of a visible image evoked by stabilized retinal stimulus of any size, color, and luminance in 1 to 3 s after its onset, is not valid in a general case. It has been demonstrated that, even with Yarbus's stabilization techniques, the lifetime of visible images varies from fractions of a second to the whole stimulus duration-up to 30 min in our experiments-depending on many factors: monocular or binocular viewing, stimulus parameters, characteristics of subjects, and so forth. The dynamics of perceived images is determined mainly by the processes at the higher levels of the visual system.
View Article and Find Full Text PDFRetinal hemodynamic oxygen reactivity assessed by perfusion velocity, blood oximetry and vessel diameter measurements.
Acta Ophthalmol
May 2015
Department of Ophthalmology, Glostrup Hospital, Glostrup, Denmark; Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
Purpose: To test the oxygen reactivity of a fundus photographic method of measuring macular perfusion velocity and to integrate macular perfusion velocities with measurements of retinal vessel diameters and blood oxygen saturation.
Methods: Sixteen eyes in 16 healthy volunteers were studied at two examination sessions using motion-contrast velocimetry and retinal oximetry with vessel diameter corrections. To test oxygen reactivity, participants were examined during normoxia, after 15 min of hyperoxia and finally after 45 min of normoxia.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!