physiology of vision

PURPOSE: The common protocol of full-field stimulus threshold (FST) testing recommends pupil dilation. The aim of this study is to investigate the difference between FST measurements with dilated and nondilated pupils in healthy subjects and patients with retinitis pigmentosa (RP). METHODS: Twenty healthy subjects and 20 RP patients were selected. One pupil of each subject was dilated; the other eye was measured in physiological width of the pupil. The FST was conducted using Diagnosys Espion E2/E3 with white, blue, and red stimuli...

No abstract text is available yet for this article.

The sense of vision begins in the retina, where light is detected and processed through a complex series of synaptic connections into meaningful information relayed to the brain via retinal ganglion cells. Light responses begin as tonic and graded signals in photoreceptors, later emerging from the retina as a series of spikes from ganglion cells. Processing by the retina extracts critical features of the visual world, including spatial frequency, temporal frequency, motion direction, color, contrast, and luminance...

PURPOSE: To report the change in the magnitude of near exodeviation in children with symptomatic convergence insufficiency successfully treated with office-based vergence/accommodative therapy in the Convergence Insufficiency Treatment Trial-Attention and Reading Trial. METHODS: A total of 131 children 9-14 years of age with symptomatic convergence insufficiency classified as successfully treated with office-based vergence/accommodative therapy at the 16-week outcome visit were included...

PURPOSE: To examine the prevalence of loneliness and associated factors in young adults with vision impairment (VI), including quality of life (QoL) in India. METHODS: Two hundred and three VI young adults (18-35 years) and 219 age-matched non-VI (controls) adults completed the loneliness scale, WHOQOL-BREF, Social Network Index (SNI) (network diversity, people in network size and number of embedded network subscales) and questions regarding sociodemographic characteristics and independent mobility...

Pig farming, a vital industry, necessitates proactive measures for early disease detection and crush symptom monitoring to ensure optimum pig health and safety. This review explores advanced thermal sensing technologies and computer vision-based thermal imaging techniques employed for pig disease and piglet crush symptom monitoring on pig farms. Infrared thermography (IRT) is a non-invasive and efficient technology for measuring pig body temperature, providing advantages such as non-destructive, long-distance, and high-sensitivity measurements...

The aim of our minireview is to provide a brief overview of the diagnosis, clinical aspects, treatment options, management, and current literature available regarding herpes simplex keratitis (HSK). This type of corneal viral infection is caused by the herpes simplex virus (HSV), which can affect several tissues, including the cornea. One significant aspect of HSK is its potential to cause recurrent episodes of inflammation and damage to the cornea. After the initial infection, the HSV can establish a latent infection in the trigeminal ganglion, a nerve cluster near the eye...

Presbyopia is a global problem with an estimated 1.3 billion patients worldwide. In the area of functional food applications, dietary supplements or herbs, there are very few reports describing the positive effects of their use. In the available literature, there is a lack of studies in humans as well as on an animal model of extracts containing, simultaneously, compounds from the polyphenol group (in particular, anthocyanins) and iridoids, so we undertook a study of the effects of a preparation composed of these compounds on a condition of the organ of vision...

The health of companion animals, particularly dogs and cats, is significantly influenced by nutrition, with vitamins playing a crucial role. Vitamin A, in particular, is indispensable, with diverse roles ranging from vision to immune modulation and reproduction. Despite its importance, the metabolism and dietary requirements of vitamin A in companion animals remain complex and not fully understood. This review provides a comprehensive overview of the historical perspective, the digestion, the metabolism, the physiological roles, the deficiency, the excess, and the interactions with other micronutrients of vitamin A in companion animals...

Presbyopia is often the first sign of ageing experienced by humans. Standardising terminology and adopting it across the BCLA CLEAR Presbyopia reports, improves consistency in the communication of the evidence-based understanding of this universal physiological process. Presbyopia can be functionally and psychologically debilitating, especially for those with poor access to eyecare. Presbyopia was defined as occurring when the physiologically normal age-related reduction in the eye's focusing range reaches a point that, when optimally corrected for far vision, the clarity of vision at near is insufficient to satisfy an individual's requirements...

INTRODUCTION: Mummy berry is a serious disease that may result in up to 70 percent of yield loss for lowbush blueberries. Practical mummy berry disease detection, stage classification and severity estimation remain great challenges for computer vision-based approaches because images taken in lowbush blueberry fields are usually a mixture of different plant parts (leaves, bud, flowers and fruits) with a very complex background. Specifically, typical problems hindering this effort included data scarcity due to high manual labelling cost, tiny and low contrast disease features interfered and occluded by healthy plant parts, and over-complicated deep neural networks which made deployment of a predictive system difficult...

Timely and accurate estimation of cotton seedling emergence rate is of great significance to cotton production. This study explored the feasibility of drone-based remote sensing in monitoring cotton seedling emergence. The visible and multispectral images of cotton seedlings with 2 - 4 leaves in 30 plots were synchronously obtained by drones. The acquired images included cotton seedlings, bare soil, mulching films, and PE drip tapes. After constructing 17 visible VIs and 14 multispectral VIs, three strategies were used to separate cotton seedlings from the images: (1) Otsu's thresholding was performed on each vegetation index (VI); (2) Key VIs were extracted based on results of (1), and the Otsu-intersection method and three machine learning methods were used to classify cotton seedlings, bare soil, mulching films, and PE drip tapes in the images; (3) Machine learning models were constructed using all VIs and validated...

In order to cause vision-disrupting fibrotic secondary cataract (PCO), lens epithelial cells that survive cataract surgery must migrate to the posterior of the lens capsule and differentiate into myofibroblasts. During this process, the cells become exposed to the FGF that diffuses out of the vitreous body. In normal development, such relatively high levels of FGF induce lens epithelial cells to differentiate into lens fiber cells. It has been a mystery as to how lens cells could instead undergo a mutually exclusive cell fate, namely epithelial to myofibroblast transition, in the FGF-rich environment of the posterior capsule...

INTRODUCTION: In this research, we introduce the NutriGreen dataset, which is a collection of images representing branded food products aimed for training segmentation models for detecting various labels on food packaging. Each image in the dataset comes with three distinct labels: one indicating its nutritional quality using the Nutri-Score, another denoting whether it is vegan or vegetarian origin with the V-label, and a third displaying the EU organic certification (BIO) logo. METHODS: To create the dataset, we have used semi-automatic annotation pipeline that combines domain expert annotation and automatic annotation using a deep learning model...

Fluorine-18-fluorodeoxyglucose (18 F-FDG) positron emission tomography (PET)/computed tomography (CT) is widely used for the detection, diagnosis, and clinical decision-making in oncological diseases. However, in daily medical practice, it is often difficult to make clinical decisions because of physiological FDG uptake or cancers with poor FDG uptake. False negative clinical diagnoses of malignant lesions are critical issues that require attention. In this study, Vision Transformer (ViT) was used to automatically classify 18 F-FDG PET/CT slices as benign or malignant...

PURPOSE: Myopic marmosets are known to exhibit significant inner retinal thinning compared to age-matched controls. The purpose of this study was to assess inner retinal activity in marmosets with lens-induced myopia compared to age-matched controls and evaluate its relationship with induced changes in refractive state and eye growth. METHODS: Cycloplegic refractive error (Rx), vitreous chamber depth (VCD), and photopic full-field electroretinogram were measured in 14 marmosets treated binocularly with negative contact lenses compared to 9 untreated controls at different stages throughout the experimental period (from 74 to 369 days of age)...

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Artificial intelligence (AI) has emerged as a transformative force with great potential in various fields, including healthcare. In recent years, AI has garnered significant attention due to its potential to revolutionise ophthalmology, leading to advancements in patient care such as disease detection, diagnosis, treatment and monitoring of disease progression. This study presents a comprehensive analysis of the research trends and collaborative networks at the intersection of AI and ophthalmology. In this study, we conducted an extensive search of the Web of Science Core Collection to identify articles related to 'artificial intelligence' in ophthalmology published from 1968 to 2023...

PURPOSE: To investigate gaze and behavioural metrics at different viewing distances with multifocal contact lenses (MFCLs), single vision contact lenses (SVCLs) and progressive addition lenses (PALs). METHODS: Fifteen presbyopic contact lens wearers participated over five separate study visits. At each visit, participants were randomly assigned to wear one of five refractive corrections: habitual PAL spectacles, delefilcon A (Alcon Inc.) MFCLs and three separate pairs of delefilcon A single vision lenses worn as distance, intermediate and near corrections...

This research aimed to (1) discover the appropriate formula for the production of Nam Dok Mai mango cheese analog products and (2) study the physical, nutritional, microbial, and sensory properties of the produced Nam Dok Mai mango cheese analogs. To investigate the appropriate formula, the factors studied included the pH value of Nam Dok Mai mango juice (2.50 or 3.00) and the proportion of salted butter (18.0% or 19.5%) and carrageenan (0.8% or 0.9%). The study was conducted by using the factorials in a completely randomized design experiment...