A5022289099- Ocular and Laser Science Research
- Visual perception and processing mechanisms
- Retinal Development and Disorders
- Retinal Diseases and Treatments
- Advanced Fluorescence Microscopy Techniques
- Optical Coherence Tomography Applications
- Glaucoma and retinal disorders
- Photoreceptor and optogenetics research
- Cultural Heritage Materials Analysis
- Nonlinear Optical Materials Studies
- Advanced Optical Sensing Technologies
- Retinal Imaging and Analysis
- Ophthalmology and Visual Impairment Studies
- Laser-induced spectroscopy and plasma
- Conservation Techniques and Studies
- Photoacoustic and Ultrasonic Imaging
- Laser Material Processing Techniques
- Analytical Chemistry and Sensors
- Infrared Target Detection Methodologies
- Laser Design and Applications
- Intraocular Surgery and Lenses
- Receptor Mechanisms and Signaling
- Nutritional Studies and Diet
- Advanced Sensor Technologies Research
- Advanced Optical Imaging Technologies
Nicolaus Copernicus University
2015-2024
Institute of Physics
2013-2024
Institute of Physical Chemistry
2020-2024
Polish Academy of Sciences
2006-2024
International Institute for Molecular Oncology
2021-2022
Czech Academy of Sciences, Institute of Physics
2019
National Marine Fisheries Research Institute
2009
Institute of Fluid Flow-Machinery
2005-2007
Polish Academy of Learning
2007
Universität Hamburg
2005
Significance This study resolves a long-standing question about the ability of humans to perceive near infrared radiation (IR) and identifies mechanism driving human IR vision. A few previous reports our expanded psychophysical studies here reveal that can detect at wavelengths longer than 1,000 nm it as visible light, finding has not received satisfactory physical explanation. We show light activates photoreceptors through nonlinear optical process. also caused photoisomerization purified...
BackgroundNoninvasive assessment of metabolic processes that sustain regeneration human retinal visual pigments (visual cycle) is essential to improve ophthalmic diagnostics and accelerate development new treatments counter diseases. Fluorescent vitamin A derivatives, which are the chemical intermediates these processes, highly sensitive UV light; thus, safe analyses in humans currently beyond reach even most modern ocular imaging modalities.MethodsWe present a compact, 2-photon-excited...
Microperimetry is a subjective ophthalmologic test used to assess retinal function at various specific and focal locations of the visual field.Historically, visible light has been described as ranging from 400 720 nm.However, we previously demonstrated that infra-red can initiate transduction in rod photoreceptors by mechanism two-photon absorption pigments.Here introduce newly designed constructed microperimeter.We provide for first time evidence presence nonlinear process occurring human...
This review discusses the current state of knowledge regarding phenomenon called two-photon vision. It involves visual perception pulsed infrared beams in range 850–1200 nm as having colors corresponding to one-half IR wavelengths. is caused by absorption (TPA), which occurs when photopigment interacts simultaneously with two photons. The physical mechanism TPA described, and implications about efficiency process are considered. spectral vision defined, along a detailed discussion known...
Humans can detect infrared light at wavelengths over 1000 nm, perceived as visible of the corresponding half wavelength. This is due to a two-photon (2P) absorption process, which requires sufficiently large amounts luminous energy. For safety reasons, this energy must be delivered by pulsed sources well focused in retina. Although effect has been known for several decades, spatial properties 2P vision comparison normal have not yet elucidated. We developed new experimental system measure,...
Two-photon microscopy allows visualization of subcellular structures in the living animal retina.In previously reported experiments it was necessary to apply a contact lens each subject.Extending this technology larger animals would require fitting custom and cumbersome placement head on microscope stage.Here we demonstrate new device, periscope, for coupling light energy into mouse eye capturing emitted fluorescence.Using periscope obtained images RPE their organelles, retinosomes, with...
Two-photon vision relies on the perception of pulsed infrared light due to two-photon absorption in visual pigments. This study aimed measure human pupil reaction caused by a 1040-nm stimulus and compare it with responses elicited 520-nm stimuli similar color.Pupillary reflex (PLR) was induced 14 dark-adapted healthy subjects. Three types fovea-centered 3.5° diameter were tested: spirals formed fast scanning (infrared [IR] laser) or (visible [VIS] laser beams uniformly filled circle created...
Abstract Glaucoma causes irreversible neuropathy, which, untreated, may lead to blindness. In this case–control study, we measured two-photon infrared (IR) light sensitivity in glaucomatous eyes propose a new method quantify the visual loss. total, 64 patients were recruited with an equal distribution between glaucoma and control groups. Retinal IR was assessed using excitation device. A fundus-driven microperimeter used measure retinal visible light. The nerve fiber layer (RNFL) thickness...
Noninvasive imaging of endogenous retinal fluorophores, including vitamin A derivatives, is vital to developing new treatments for diseases. Here, we present a protocol obtaining in vivo two-photon excited fluorescence images the fundus human eye. We describe steps laser characterization, system alignment, positioning subjects, and data registration. detail processing demonstrate analysis with example datasets. This technique allays safety concerns by allowing acquisition informative at low...
Two-photon vision is a phenomenon associated with the perception of short pulses near-infrared radiation (900-1200 nm) as visible light. It caused by nonlinear process two-photon absorption visual pigments. Here we present results showing influence pulse duration and repetition rate pulsed lasers on threshold. We compared sensitivity maps retina obtained for subjects normal using cost-effective fiber laser ( λ c = 1028.4 nm, τ p 12.2 ps, F rep 19.17 MHz) solid-state 1043.3 0.253 62.65 MHz)....
This report presents the results of measurements two-photon vision threshold for various pulse trains. We employed three pulsed near-infrared lasers and stretchers to obtain variations duty cycle parameter over orders magnitude. proposed extensively described a mathematical model that combines laser parameters with visual value. The presented methodology enables one predict value stimulus healthy subject while using source known parameters. Our findings would be engineers community...
Purpose: The eye can see pulsed near-infrared (IR) radiation with the color corresponding to half of wavelength used. Until recently, technology required for measuring IR vision was confined optical laboratories and not studied clinically. current investigation sought determine values thresholds in a healthy population. Methods: IR-light threshold measured 45 participants, aged from 21 70 years. Ten patients retinal pathology were included comparison. Ocular media clarity assessed straylight...
We report the development of a widely-tunable femtosecond fiber laser system and its application for two-photon vision studies. The source is based on an Er-doped with spectral shift up to 2150 nm, followed by second harmonic generation module generate frequency-doubled beam tunable from 872 1075 nm. delivers sub-230 fs pulses nearly-constant duration over entire tuning range, output powers between 0.68-1.24 mW, which corresponds pulse energy 13.2-24.1 pJ. Such sufficient employing...
In this paper we present a multimodal device for imaging fundus of human eye in vivo which combines functionality autofluorescence by confocal SLO with Fourier domain OCT.Native fluorescence was excited modulated laser beam (λ = 473 nm, 20 MHz) and lock-in detection applied resulting improving sensitivity.The setup allows acquisition high resolution OCT contrast AF images using excitation power 50-65 μW without averaging consecutive images.Successful functioning constructed have been...
The recently introduced term “two-photon vision” relates to the visual perception resulting from a simultaneous absorption of two photons by photoreceptors. In this study, we determined two-photon retinal sensitivity in age-related macular degeneration (AMD) and compared it that normal aging. Microperimetry was performed with visible (white) light infrared (IR) light, which perceived as green stimulation. total, 45 subjects were included one (better) eye studied. Furthermore, best-corrected...
Two-photon absorption occurring in photoreceptors of human eye is responsible for perception pulsed infrared laser beams. Color perceived light corresponds to about half wavelength stimulating beam. This recently discovered phenomenon called two-photon vision. However it yet not clear how such phenomena could impact an ophthalmic diagnosis and therefore further studies are required. In this paper we present the system that enables future psychophysical experiments extend knowledge vision its...
Pulsed near-infrared (NIR) light sources can be successfully applied for both imaging and functional testing of the human eye, as published recently. These two groups applications have different requirements. For applications, most preferable is invisible scanning beam while efficiently visible stimulating applications. The eye using NIR laser beams possible due to two-photon vision (2PV) phenomenon. 2PV enables perception pulsed color corresponding approximately half wavelength. This study...
In this work, we present a pipeline for processing data acquired during in vivo optoretinography measurements of human photoreceptors' response to light with Spatio-Temporal Optical Coherence Tomography (STOC-T) setup.
Two-photon vision is a new and developing field in science. The phenomenon based on visual perception of pulsed infrared lasers (800-1300 nm) due to the isomerization pigments caused by two-photon absorption, with color corresponding wavelength about one-half stimulating near-infrared spectral range. Future applications this effect, both medical diagnostics virtual/augmented reality (VR/AR), require ability determine luminance stimuli. However, luminous efficiency function V ( λ ) outside...
The aim of this paper is to present a novel method, called Adaptive Edge Detection (AED), extraction precise pupil edge coordinates from eye image characterized by reflections external illuminators and laser beams. method used for monitoring size position during psychophysical tests two-photon vision performed dedicated optical set-up. Two-photon new phenomenon perception short-pulsed near infrared beams focused on human retina as having color half their wavelength it caused absorption...