A5058879057- Optical Polarization and Ellipsometry
- Visual perception and processing mechanisms
- Orbital Angular Momentum in Optics
- Ocular Surface and Contact Lens
- Tactile and Sensory Interactions
- Corneal surgery and disorders
- Color Science and Applications
- Photoreceptor and optogenetics research
- Neurobiology and Insect Physiology Research
- Retinal Imaging and Analysis
- Olfactory and Sensory Function Studies
- Color perception and design
- Ergonomics and Musculoskeletal Disorders
- Neural dynamics and brain function
- EEG and Brain-Computer Interfaces
- Ophthalmology and Visual Impairment Studies
- Glaucoma and retinal disorders
- Advanced Optical Sensing Technologies
University of Waterloo
2023-2024
The human ability to perceive the polarization state of blue light through a phenomenon known as Haidinger's brush is important, due its link ocular diseases like macular degeneration, but utility limited by lack interpretable outcome measures. This study uses structured create polarization-defined entoptic images that vary purely along radial direction, with apparent sizes can be directly measured and interpreted. methods presented here offer another dimension exploration complement...
The ability to perceive polarization-related entoptic phenomena arises from the dichroism of macular pigments held in Henle’s fiber layer retina and can be inhibited by retinal diseases, such as age-related degeneration, which alters structure macula. Structured light tools enable direct probing pigment density through perception polarization-dependent patterns. Here, we directly measure visual angle an pattern created illumination with a structured state task that is insensitive corneal...
To characterize the optical density of circularly oriented macular pigment (MP) in human retina, as a quantification health, Psychophysical discrimination tests were performed on subjects using structured light-induced entoptic phenomena. Central exclusions used to determine visual extents stimuli with varying spatiotemporal frequencies. A model was developed describe action MP, and map perceived sizes. The experimental results provided validation for computational model, showing good...
The ability to perceive polarization-related entoptic phenomena arises from the dichroism of macular pigments held in Henle's fiber layer retina and can be inhibited by retinal diseases such as age-related degeneration, which alter structure macula. Structured light tools enable direct probing pigment density through perception polarization-dependent patterns. Here, we directly measure visual angle an pattern created illumination with a structured state task that is insensitive corneal...
The incorporation of structured light techniques into vision science has enabled more selective probes polarization related entoptic phenomena. Diverse sets stimuli have become accessible in which the spatially dependant optical properties can be rapidly controlled and manipulated. For example, past studies with human perception dealt that appear to vary azimuthally. This is mainly due constraint typically available degree freedom manipulate phase shift rotates perceived pattern around a...
To identify the stimulus airflow characteristics and confirm consistency of a novel air jet-based aesthesiometer capable producing applying multiple stimuli separated either by time and/or space.A (Dolphin Aesthesiometer) was designed around micro-blower under software management. Two nozzle attachments assisted in control (flexible tube 1.6 mm diameter; brass 0.5 diameter). Four studies that tested were completed: (i) pattern/trajectory, (ii) surface dispersion, (iii) force across range...
Aims/Purpose: To report the development of a novel, air‐based, aesthesiometer capable producing and applying multiple stimuli differing intensity, separated by time and/or ocular surface location. Methods: Individual micro‐blowers (Murata Manufacturing Co., Japan) were combined with an exit airflow nozzle into integrated stimulus unit (ISU) that produced controlled through exit. Stimulus duration, repetition, as feature airflow, was managed for each ISU using designed software. The software...
Abstract Purpose To assess the feasibility of using multifunction instruments to measure axial length for monitoring myopia progression in children and adults. Methods Axial was measured 60 (aged 6–18 years) adults 19–50 with (Myah Myopia Master) stand‐alone biometers (Lenstar LS900 IOLMaster 700). Repeatability (measurements by same examiner) reproducibility different examiners) were computed as within‐subject standard deviation (Sw) 95% limits agreement (LoA). Inter‐instrument intraclass...
The macular pigment (MP) in the radially-oriented Henle fibers that surround foveola enables ability to perceive orientation of polarized blue light through an entoptic phenomena known as Haidinger's brush. MP has been linked eye diseases and central field dysfunctions, most notably age-related degeneration (AMD), a globally leading cause irreversible blindness. Recent integration structured techniques into vision science allowed for development more selective versatile probes health provide...
The dichroic macular pigment in the eye acts as a natural radial polarization filter and enables humans to directly perceive polarization-related entoptic phenomena. Linearly polarized blue light induces subtle bowtie-like pattern known Haidinger’s brush central point of vision. clarity shape this perceived are linked health macula, rendering potential diagnostic marker research on early-stage age-related degeneration (AMD) field visual dysfunction. However, due faint nature signal,...
Psychophysical discrimination of structured light (SL) stimuli may be useful in screening for various macular disorders, including degenerative diseases. The circularly-oriented pigment optical density (coMPOD), calculated from the performance SL-induced entoptic phenomena, reveal a novel functional biomarker health. In this study, we investigated potential influence eye dominance and testing order effects on SL-based stimulus perception, factors that potentially sensitivity tests based SL...
Abstract Purpose To assess the ability of Dolphin air‐pulse aesthesiometer to present multiple stimuli, which are separated temporally (in sequence) or spatially (simultaneously). Methods Two studies were performed explore cooling effects induced by double air‐puff stimuli generated a novel composed two micro‐blower integrated units. The delivered sequentially simultaneously at same different spatial locations an in vitro eye model monitored using thermography. was based on 2‐cm LED dome...
Macular pigment is thought to underlie entoptic percepts that enable human discrimination of polarized light. Therefore, polarization sensitivity may be a useful probe macular density and the risk future disease. Structured light beams formed through spin coupled orbital angular momentum states exhibit spatially dependent are therefore ideally suited quantify sensitivity. When fixating at center these beams, polarization-defined percept resembling radial spokes observed. Using such...
Abstract We investigated the ability of two non-invasive transcranial electrical stimulation (tES) protocols targeting early visual areas to improve peripheral word recognition in separate within-subject, double-blind, sham-controlled experiments with normal observers. English sentences were presented 10 degrees below fixation using a rapid serial presentation (RSVP). Transcranial random noise (tRNS) applied bilaterally on either size occipital pole (Oz) elicited significant performance...