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1.
J Refract Surg ; 38(8): 497-501, 2022 Aug.
Article in English | MEDLINE | ID: mdl-35947002

ABSTRACT

PURPOSE: To investigate extended depth of focus intraocular lenses (EDOF IOLs), intended to extend the depth of field after cataract surgery in a comparative study at the optical bench. METHODS: An optical bench with either green or white light was used for this study. The artificial cornea used exhibited a spherical aberration of 0.2 µm. Examinations of the following lenses with a pupil opening of 3 and 4.5 mm were carried out: AcrySof IQ Vivity (Alcon Laboratories, Inc), Isopure (PhysIOL), Tecnis Eyhance (Johnson & Johnson), Vivinex Impress (Hoya Surgical Optics), and xact (Santen). RESULTS: Using green light and a pupil aperture of 3 mm, the AcrySof IQ Vivity showed the highest light energy for the intermediate area, whereas the Isopure and Vivinex Impress provided the highest energy for distance vision. Under the same examination conditions with a pupil opening of 4.5 mm, all lenses showed a low light distribution for the intermediate range. Regarding light distribution for distance, the Tecnis Eyhance had the highest light intensity. Using white light, the curves became much wider and more similar to each other. CONCLUSIONS: The five EDOF lenses investigated differ mainly by their different weighting of energy between the far and intermediate ranges. [J Refract Surg. 2022;38(8):497-501.].


Subject(s)
Depth Perception , Lenses, Intraocular , Depth Perception/physiology , Humans , Optics and Photonics , Prosthesis Design , Pupil/physiology , Vision, Ocular
2.
Opt Lett ; 47(15): 3876-3879, 2022 Aug 01.
Article in English | MEDLINE | ID: mdl-35913345

ABSTRACT

Augmented reality (AR) near-eye displays (NEDs) are emerging as the next-generation display platform. The existing AR NED only present one single video channel at a time, same as traditional media such as TVs and smartphones. In this Letter, to the best of our knowledge, we propose for the first time a multi-channel holographic retinal projection display (RPD), which can provide multi-channel image sources simultaneously, thus greatly increasing the information content. Due to the superposition capacity of a hologram, multiple images are projected to different viewpoints simultaneously through multiple spherical wave encoding, so that the viewer can switch among playing channels very fast through eye rotation. A full-color dynamic multi-channel holographic near-eye display is demonstrated in the optical experiment. The proposed method provides a good prospect that the future AR glasses can play dozens of video channels in parallel, and the user can switch among channels freely and efficiently just through a simple eye rotation.


Subject(s)
Holography , Holography/methods , Retina/diagnostic imaging , Vision, Ocular
3.
Opt Lett ; 47(15): 3892-3895, 2022 Aug 01.
Article in English | MEDLINE | ID: mdl-35913340

ABSTRACT

We propose and experimentally demonstrate an optical processor for a binarized neural network (NN). Implementation of a binarized NN involves multiply-accumulate operations, in which positive and negative weights should be implemented. In the proposed processor, the positive and negative weights are realized by switching the operations of a dual-drive Mach-Zehnder modulator (DD-MZM) between two quadrature points corresponding to two binary weights of +1 and -1, and the multiplication is also performed at the DD-MZM. The accumulation operation is realized by dispersion-induced time delays and detection at a photodetector (PD). A proof-of-concept experiment is performed. A binarized convolutional neural network (CNN) accelerated by the optical processor at a speed of 32 giga floating point operations/s (GFLOPS) is tested on two benchmark image classification tasks. The large bandwidth and parallel processing capability of the processor has high potential for next generation data computing.


Subject(s)
Neural Networks, Computer , Vision, Ocular , Equipment Design
4.
Optom Vis Sci ; 99(8): 613-615, 2022 Aug 01.
Article in English | MEDLINE | ID: mdl-35930258
5.
J. optom. (Internet) ; 15(3)Jul-Sep.2022. graf, ilus
Article in English | IBECS | ID: ibc-204703

ABSTRACT

Objective: The main objective of this study was to obtain percentile curves of stereoacuity in arc seconds for a Spanish population aged between three and twelve years of age.Materials and methods: A descriptive, observational and transversal study was conducted, which included children aged between three and twelve years of age who did not present with any known ocular and/or systemic diseases. The convenience sampling method was used to select the sample from three schools and one hospital in the Community of Madrid. The Bueno-Matilla Vision Unit's random dot test was used to measure stereoacuity. A descriptive statistic was performed with the stereoacuity values that were obtained for the 5th, 10th, 25th, 50th, 75th, 90th and 95th percentiles.Results: The stereoacuity values of 1300 children were analysed. In the 50th percentile curve, it was determined that stereoacuity values close to 40 sec/arc were present from four years of age, and at four years and nine months, stereoacuity values close to 28 sec/arc were already being observed within said percentile, with values that were similar to those expected in the adult population. A progressive increase was observed, reaching 19 sec/arc before six years of age, with this stereoacuity value becoming more established in children from seven years of age.Conclusion: Although given the specific type of sampling that was performed it was not possible to generalise the results to the entire population, these percentile curves may aid paediatric professionals in their assessment of the development of this visual ability, which is indicative of the degree of development of binocular vision. (AU)


Subject(s)
Humans , Child, Preschool , Child , Vision Tests , Vision, Ocular , Vision, Binocular , Depth Perception , Visual Acuity , Cross-Sectional Studies , Epidemiology, Descriptive
6.
Sci Rep ; 12(1): 11427, 2022 Jul 06.
Article in English | MEDLINE | ID: mdl-35794174

ABSTRACT

The present study examined the perceptual consequences of learning arbitrary mappings between visual stimuli and hand movements. Participants moved a small cursor with their unseen hand twice to a large visual target object and then judged either the relative distance of the hand movements (Exp.1), or the relative number of dots that appeared in the two consecutive target objects (Exp.2) using a two-alternative forced choice method. During a learning phase, the numbers of dots that appeared in the target object were correlated with the hand movement distance. In Exp.1, we observed that after the participants were trained to expect many dots with larger hand movements, they judged movements made to targets with many dots as being longer than the same movements made to targets with few dots. In Exp.2, another group of participants who received the same training judged the same number of dots as smaller when larger rather than smaller hand movements were executed. When many dots were paired with smaller hand movements during the learning phase of both experiments, no significant changes in the perception of movements and of visual stimuli were observed. These results suggest that changes in the perception of body states and of external objects can arise when certain body characteristics co-occur with certain characteristics of the environment. They also indicate that the (dis)integration of multimodal perceptual signals depends not only on the physical or statistical relation between these signals, but on which signal is currently attended.


Subject(s)
Psychomotor Performance , Visual Perception , Hand , Humans , Movement , Vision, Ocular
7.
Sci Rep ; 12(1): 11567, 2022 Jul 07.
Article in English | MEDLINE | ID: mdl-35798929

ABSTRACT

The human brain can form cognitive maps of a spatial environment, which can support wayfinding. In this study, we investigated cognitive map formation of an environment presented in the tactile modality, in visually impaired and sighted persons. In addition, we assessed the acquisition of route and survey knowledge. Ten persons with a visual impairment (PVIs) and ten sighted control participants learned a tactile map of a city-like environment. The map included five marked locations associated with different items. Participants subsequently estimated distances between item pairs, performed a direction pointing task, reproduced routes between items and recalled item locations. In addition, we conducted questionnaires to assess general navigational abilities and the use of route or survey strategies. Overall, participants in both groups performed well on the spatial tasks. Our results did not show differences in performance between PVIs and sighted persons, indicating that both groups formed an equally accurate cognitive map. Furthermore, we found that the groups generally used similar navigational strategies, which correlated with performance on some of the tasks, and acquired similar and accurate route and survey knowledge. We therefore suggest that PVIs are able to employ a route as well as survey strategy if they have the opportunity to access route-like as well as map-like information such as on a tactile map.


Subject(s)
Self-Help Devices , Spatial Navigation , Cognition , Humans , Learning , Touch , Vision, Ocular
8.
Biomed Res Int ; 2022: 8608892, 2022.
Article in English | MEDLINE | ID: mdl-35782056

ABSTRACT

Thanks to the discovery of human eye photoreceptor cells, ipGRC and human nonvisual channels, the nonvisual effects of light have gradually come to our vision and been rationally utilized. Along with this trend, people have expanded their demand for the light environment to both visual and nonvisual needs from only visual needs. With a good natural daylighting, parturients will find their psychological pressure and physiological pain relieved, their rehabilitation rate increased, and they get rehabilitated more quickly. This study was carried out in a representative maternity ward in Harbin based on the latest research results on nonvisual effects at home and abroad. Specifically, the nonvisual effects on the natural light environment in the ward throughout the year were simulated and analyzed from the aspects of equivalent melanopic lux (EML), stimulus frequency (Stim.freq), and circadian effective area (CEA). During the study, natural light in the ward was measured on site, and the evaluation tool and workflow of nonvisual effects were created with the aid of Grasshopper modeling platform, Ladybug+Honeybee, and VB script editor. The results show that the nonvisual effects of natural light on the body of parturients gradually weaken as they further go inside the ward. What is worse, in the most unfavorable all-overcast condition, daylighting on beds far away from the window does not meet the stimulus of human circadian rhythm from April to August. Therefore, additional light is required. The wards have the best nonvisual natural light environment when they are south facing and have a window to floor ratio of 0.3.


Subject(s)
Circadian Rhythm , Photoreceptor Cells , Animals , Bees , Environment , Female , Hospitals , Humans , Pregnancy , Vision, Ocular
9.
Sensors (Basel) ; 22(13)2022 Jun 22.
Article in English | MEDLINE | ID: mdl-35808199

ABSTRACT

The detection of moving objects is one of the key problems in the field of computer vision. It is very important to detect moving objects accurately and rapidly for automatic driving. In this paper, we propose an improved moving object detection method to overcome the disadvantages of the RGB information-only-based method in detecting moving objects that are susceptible to shadow interference and illumination changes by adding depth information. Firstly, a convolutional neural network (CNN) based on the color edge-guided super-resolution reconstruction of depth maps is proposed to perform super-resolution reconstruction of low-resolution depth images obtained by depth cameras. Secondly, the RGB-D moving object detection algorithm is based on fusing the depth information of the same scene with RGB features for detection. Finally, in order to evaluate the effectiveness of the algorithm proposed in this paper, the Middlebury 2005 dataset and the SBM-RGBD dataset are successively used for testing. The experimental results show that our super-resolution reconstruction algorithm achieves the best results among the six commonly used algorithms, and our moving object detection algorithm improves the detection accuracy by up to 18.2%, 9.87% and 40.2% in three scenes, respectively, compared with the original algorithm, and it achieves the best results compared with the other three recent RGB-D-based methods. The algorithm proposed in this paper can better overcome the interference caused by shadow or illumination changes and detect moving objects more accurately.


Subject(s)
Image Processing, Computer-Assisted , Neural Networks, Computer , Algorithms , Image Processing, Computer-Assisted/methods , Vision, Ocular
10.
Sensors (Basel) ; 22(13)2022 Jun 23.
Article in English | MEDLINE | ID: mdl-35808239

ABSTRACT

We present a workflow for seamless real-time navigation and 3D thermal mapping in combined indoor and outdoor environments in a global reference frame. The automated workflow and partly real-time capabilities are of special interest for inspection tasks and also for other time-critical applications. We use a hand-held integrated positioning system (IPS), which is a real-time capable visual-aided inertial navigation technology, and augment it with an additional passive thermal infrared camera and global referencing capabilities. The global reference is realized through surveyed optical markers (AprilTags). Due to the sensor data's fusion of the stereo camera and the thermal images, the resulting georeferenced 3D point cloud is enriched with thermal intensity values. A challenging calibration approach is used to geometrically calibrate and pixel-co-register the trifocal camera system. By fusing the terrestrial dataset with additional geographic information from an unmanned aerial vehicle, we gain a complete building hull point cloud and automatically reconstruct a semantic 3D model. A single-family house with surroundings in the village of Morschenich near the city of Jülich (German federal state North Rhine-Westphalia) was used as a test site to demonstrate our workflow. The presented work is a step towards automated building information modeling.


Subject(s)
Imaging, Three-Dimensional , Semantics , Calibration , Thermography , Vision, Ocular
11.
Sensors (Basel) ; 22(13)2022 Jun 24.
Article in English | MEDLINE | ID: mdl-35808291

ABSTRACT

Spatial cognition is a daily life ability, developed in order to be able to understand and interact with our environment. Even if all the senses are involved in mental representation of space elaboration, the lack of vision makes it more difficult, especially because of the importance of peripheral information in updating the relative positions of surrounding landmarks when one is moving. Spatial audio technology has long been used for studies of human perception, particularly in the area of auditory source localisation. The ability to reproduce individual sounds at desired positions, or complex spatial audio scenes, without the need to manipulate physical devices has provided researchers with many benefits. We present a review of several studies employing the power of spatial audio virtual reality for research in spatial cognition with blind individuals. These include studies investigating simple spatial configurations, architectural navigation, reaching to sounds, and sound design for improved acceptability. Prospects for future research, including those currently underway, are also discussed.


Subject(s)
Sound Localization , Virtual Reality , Cognition , Humans , Space Perception , Vision, Ocular
12.
Sensors (Basel) ; 22(13)2022 Jun 30.
Article in English | MEDLINE | ID: mdl-35808444

ABSTRACT

Currently, the analysis of human motion is one of the most interesting and active research topics in computer science, especially in computer vision [...].


Subject(s)
Vision, Ocular , Humans , Motion
13.
Comput Intell Neurosci ; 2022: 2910531, 2022.
Article in English | MEDLINE | ID: mdl-35800689

ABSTRACT

Functions such as Internet browsing and online shopping have a great impact on people's lives. The footprints of people browsing various information and news on the web page are also increasing year by year. More and more people begin to pay attention to the visual communication in web design. Network information is widely loved by people because of its convenience, quickness, and simplicity. In order to study the visual problem in network information, this paper proposes to use a feature matching algorithm to study the visual information transmission in web design. Using stereo vision and feature matching algorithm, the target recognition function in the visual communication of web design is realized. The content of web design is defined from the perspective of visual beauty and overall harmony. By extracting the feature points in the data, the two-dimensional vision is transformed into a three-dimensional vision. It not only can accurately extract feature points from data but also can convert 2D vision to 3D vision. Finally, in order to optimize the feature matching speed of web design images, the epipolar constraint algorithm is used to optimize the feature matching function. The experimental results show that the content of this paper can truly show the virtual effect in web design and can intuitively upload and transmit simple and rich information content. This paper not only meets the aesthetic needs of the public for web design but also improves the problem of fuzzy information in the process of visual information transmission.


Subject(s)
Algorithms , Depth Perception , Humans , Vision, Ocular
14.
Vestn Oftalmol ; 138(3): 95-101, 2022.
Article in Russian | MEDLINE | ID: mdl-35801887

ABSTRACT

Loss of vision is a pressing medical and social problem leading to profound disability, loss of ability to work, serious alterations in the psycho-emotional state, and a decline of the quality of life. When conservative or surgical treatment can not help restore vision, the use of visual prosthesis - bionic eye - can be an effective solution. This review covers the main modern approaches to the development of visual prosthetic systems. Analysis of publications revealed that there are several main approaches to visual prosthesis differing primarily by the anatomical structure targeted for stimulation in order to activate visual sensations. The most significant among them are retinal prostheses, optic nerve stimulation, and cortical visual prostheses. Currently, retinal prostheses such as ARGUS II demonstrate the most successful results, since the stimulation of the surviving neural structures of the retina is a relatively easy task, but their field of application is limited to diseases associated with pathological changes in photoreceptors. The development of cortical visual prostheses is more difficult, but in the future they may allow using more stimulation channels to obtain a more detailed visual perception. In addition, cortical visual prostheses are universal, as they do not require preservation of any structures of the visual organ, only the primary visual cortex.


Subject(s)
Bionics , Visual Prosthesis , Humans , Quality of Life , Retina , Vision, Ocular
15.
Annu Rev Neurosci ; 45: 471-489, 2022 07 08.
Article in English | MEDLINE | ID: mdl-35803589

ABSTRACT

Unimodal sensory loss leads to structural and functional changes in both deprived and nondeprived brain circuits. This process is broadly known as cross-modal plasticity. The evidence available indicates that cross-modal changes underlie the enhanced performances of the spared sensory modalities in deprived subjects. Sensory experience is a fundamental driver of cross-modal plasticity, yet there is evidence from early-visually deprived models supporting an additional role for experience-independent factors. These experience-independent factors are expected to act early in development and constrain neuronal plasticity at later stages. Here we review the cross-modal adaptations elicited by congenital or induced visual deprivation prior to vision. In most of these studies, cross-modal adaptations have been addressed at the structural and functional levels. Here, we also appraise recent data regarding behavioral performance in early-visually deprived models. However, further research is needed to explore how circuit reorganization affects their function and what brings about enhanced behavioral performance.


Subject(s)
Neuronal Plasticity , Sensory Deprivation , Brain , Humans , Neuronal Plasticity/physiology , Sensory Deprivation/physiology , Vision, Ocular
16.
Curr Biol ; 32(13): R741-R743, 2022 Jul 11.
Article in English | MEDLINE | ID: mdl-35820384

ABSTRACT

Mice detect decreases in illumination in dim light near the visual threshold with OFF retinal ganglion cells.


Subject(s)
Vision, Ocular , Visual Perception , Animals , Lighting , Mice , Photic Stimulation , Retinal Ganglion Cells
17.
Nat Commun ; 13(1): 3853, 2022 Jul 04.
Article in English | MEDLINE | ID: mdl-35788594

ABSTRACT

Electronic visual prostheses, or biomimetic eyes, have shown the feasibility of restoring functional vision in the blind through electrical pulses to initiate neural responses artificially. However, existing visual prostheses predominantly use wired connections or electromagnetic waves for powering and data telemetry, which raises safety concerns or couples inefficiently to miniaturized implant units. Here, we present a flexible ultrasound-induced retinal stimulating piezo-array that can offer an alternative wireless artificial retinal prosthesis approach for evoking visual percepts in blind individuals. The device integrates a two-dimensional piezo-array with 32-pixel stimulating electrodes in a flexible printed circuit board. Each piezo-element can be ultrasonically and individually activated, thus, spatially reconfigurable electronic patterns can be dynamically applied via programmable ultrasound beamlines. As a proof of concept, we demonstrate the ultrasound-induced pattern reconstruction in ex vivo murine retinal tissue, showing the potential of this approach to restore functional, life-enhancing vision in people living with blindness.


Subject(s)
Visual Prosthesis , Animals , Biomimetics , Blindness/therapy , Humans , Mice , Retina/diagnostic imaging , Retina/physiology , Retina/surgery , Vision, Ocular
18.
Commun Biol ; 5(1): 692, 2022 Jul 12.
Article in English | MEDLINE | ID: mdl-35821404

ABSTRACT

Visual perception remains stable across saccadic eye movements, despite the concurrent strongly disruptive visual flow. This stability is partially associated with a reduction in visual sensitivity, known as saccadic suppression, which already starts in the retina with reduced ganglion cell sensitivity. However, the retinal circuit mechanisms giving rise to such suppression remain unknown. Here, we describe these mechanisms using electrophysiology in mouse, pig, and macaque retina, 2-photon calcium imaging, computational modeling, and human psychophysics. We find that sequential stimuli, like those that naturally occur during saccades, trigger three independent suppressive mechanisms in the retina. The main mechanism is triggered by contrast-reversing sequential stimuli and originates within the receptive field center of ganglion cells. It does not involve inhibition or other known suppressive mechanisms like saturation or adaptation. Instead, it relies on temporal filtering of the inherently slow response of cone photoreceptors coupled with downstream nonlinearities. Two further mechanisms of suppression are present predominantly in ON ganglion cells and originate in the receptive field surround, highlighting another disparity between ON and OFF ganglion cells. The mechanisms uncovered here likely play a role in shaping the retinal output following eye movements and other natural viewing conditions where sequential stimulation is ubiquitous.


Subject(s)
Retina , Saccades , Animals , Humans , Mice , Photic Stimulation/methods , Retina/physiology , Swine , Vision, Ocular , Visual Perception/physiology
19.
Comput Math Methods Med ; 2022: 6454550, 2022.
Article in English | MEDLINE | ID: mdl-35774301

ABSTRACT

In order to shorten the image registration time and improve the imaging quality, this paper proposes a fuzzy medical computer vision image information recovery algorithm based on the fuzzy sparse representation algorithm. Firstly, by constructing a computer vision image acquisition model, the visual feature quantity of the fuzzy medical computer vision image is extracted, and the feature registration design of the fuzzy medical computer vision image is carried out by using the 3D visual reconstruction technology. Then, by establishing a multidimensional histogram structure model, the wavelet multidimensional scale feature detection method is used to achieve grayscale feature extraction of fuzzy medical computer vision images. Finally, the fuzzy sparse representation algorithm is used to automatically optimize the fuzzy medical computer vision images. The experimental results show that the proposed method has a short image information registration time, less than 10 ms, and has a high peak PSNR. When the number of pixels is 700, its peak PSNR can reach 83.5 dB, which is suitable for computer image restoration.


Subject(s)
Algorithms , Fuzzy Logic , Computer Simulation , Computers , Humans , Image Processing, Computer-Assisted/methods , Vision, Ocular
20.
Genome Biol Evol ; 14(8)2022 Aug 03.
Article in English | MEDLINE | ID: mdl-35866587

ABSTRACT

Harsh environments provide opportunities to study how different species adapt, at the molecular level, to similar environmental stressors. High hydrostatic pressure, low temperature, and absence of sunlight in the deep-sea environment are challenging conditions for gene expression, cell morphology and vision. Adaptation of fish to this environment appears independently in at least 22 orders of fish, but it remains uncertain whether these adaptations represent convergent evolution. In this study, we performed comparative genomic analysis of 80 fish species to determine genetic evidences for adaptations to the deep-sea environment. The 80 fishes were divided into six groups according to their order. Positive selection and convergent evolutionary analysis were performed and functional enrichment analysis of candidate genes was performed. Positively selected genes (pik3ca, pik3cg, vcl and sphk2) were identified to be associated with the cytoskeletal response to mechanical forces and gene expression. Consistent signs of molecular convergence genes (grk1, ednrb, and nox1) in dark vision, skin color, and bone rarefaction were revealed. Functional assays of Grk1 showed that the convergent sites improved dark vision in deep-sea fish. By identifying candidate genes and functional profiles potentially involved in cold, dark, and high-pressure responses, the results of this study further enrich the understanding of fish adaptations to deep-sea environments.


Subject(s)
Adaptation, Physiological , Fishes , Acclimatization/genetics , Adaptation, Physiological/genetics , Animals , Cold Temperature , Evolution, Molecular , Fishes/genetics , Vision, Ocular
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