scholarly journals Optically correcting visual acuity beyond 20/20 improves visual perception: A cautionary tale for studies of special populations

2016 ◽  
Vol 16 (12) ◽  
pp. 241
Author(s):  
Lisa Cruz ◽  
Brian Keane ◽  
Sabine Kastner ◽  
Thomas Papathomas ◽  
Steven Silverstein
Keyword(s):  
Visual Acuity ◽  
Visual Perception ◽  
Special Populations ◽  
Cautionary Tale

scholarly journals Visual acuity differences within the normal range strongly alter visual perception: A cautionary tale for studies of special populations

2015 ◽  
Vol 15 (12) ◽  
pp. 324
Author(s):  
Matthew Roche ◽  
Brian Keane ◽  
Sabine Kastner ◽  
Thomas Papathomas ◽  
Steven Silverstein
Keyword(s):  
Visual Acuity ◽  
Visual Perception ◽  
Special Populations ◽  
Cautionary Tale ◽  
Normal Range

Neuro-ophthalmology: Disorders of Visual Perception, Pupils, and Eyelids

2021 ◽  
pp. 821-833
Author(s):  
Shivram Kumar ◽  
Kelly D. Flemming
Keyword(s):  
Visual Acuity ◽  
Visual Field ◽  
Visual Perception ◽  
Visual Loss ◽  
Visual Field Defects ◽  
Clinical Disorders ◽  
Physical Findings ◽  
Abnormal Visual ◽  
Visual Changes ◽  
Field Defects

Visual loss may develop acutely, subacutely, or insidiously. The course may be transient, static, or progressive. This chapter reviews the causes, diagnosis, and treatment of various disorders resulting in visual loss or abnormal visual perception. In addition, it reviews clinical disorders of the eyelids and pupils. Disorders of visual perception involve visual acuity, color perception, visual field defects, and other visual changes. Historical information and physical findings on examination can help to localize the problem and define the cause.

Special Visual Assessment Techniques for Multiply Handicapped Persons

1991 ◽  
Vol 85 (1) ◽  
pp. 23-29 ◽  
Author(s):  
A. Hall ◽  
D. Orel-Bixler ◽  
G. Haegerstrom-Portnoy
Keyword(s):  
Visual Acuity ◽  
Visual Evoked Potential ◽  
Evoked Potential ◽  
Visual Fields ◽  
Visual Assessment ◽  
Special Populations ◽  
Assessment Techniques ◽  
Major Emphasis ◽  
Ocular Health ◽  
Multihandicapped Persons

Techniques to assess vision capabilities of multihandicapped persons are discussed as used in a specialty Optometric clinic. The major emphasis of the assessment is to obtain information about visual abilities and to make recommendations that promote optimum vision functioning. Techniques for working with children from special populations are discussed. The assessment includes a modified ophthalmic examination to identify and correct refractive error and to assess oculomotor functioning and ocular health. Visual acuity is measured using preferential looking and visual evoked potential techniques. Confrontation visual fields are measured. Several aspects of visual function are assessed with a parent interview.

SYSTEM FOR MEASURING RODENTS' VISUAL FUNCTION: DESIGN AND IMPLEMENTATION

2014 ◽  
Vol 26 (02) ◽  
pp. 1450018 ◽  
Author(s):  
Carlos Perez-Vidal ◽  
Alejandro Garcia ◽  
Nicolas Garcia-Aracil ◽  
Jose M. Sabater ◽  
Eduardo Fernandez
Keyword(s):  
Computer Vision ◽  
Visual Acuity ◽  
Visual Perception ◽  
Contrast Sensitivity ◽  
Visual Function ◽  
Histological Analysis ◽  
Visual Development ◽  
New Drugs ◽  
Design And Implementation ◽  
Function Design

The aim of the work presented in this paper is the design, manufacturing and assembling of a system able to measure rodents' (mice and rats) visual function and to study the evolution of degenerative retina diseases. Measurement of contrast sensitivity and visual acuity is essential to design new drugs and understand mechanisms of visual development to evaluate treatments' effectiveness. Classical methods to study visual perception of animals such as electroretinogram (ERG) or histological analysis are not supplying enough information because connection between eyes and brain is not considered. The system proposed in this work consists of four screens forming a cube with black methacrylate plastic floor and roof. Screens display visual stimulus and the rodent's behaviour (placed over a platform in the middle of the cube) is analized to determine its visual acuity and contrast sensitivity. These visual stimuli are generated from a FPGA board designed in this project. This board has a USB link with a computer and it controls screens via VGA signals. Rodents' behaviour is analized using computer vision algorithms under OpenCV libraries. To test the system, more than 30 mice (C57 and RD10 type) have been used to validate the hardware, the software, the procedure and protocol.

Large-Scale LOD Adaptive Terrain Rendering

2012 ◽  
Vol 220-223 ◽  
pp. 2450-2453 ◽  
Author(s):  
Wen Long Yu ◽  
Li Min Zhang ◽  
Bing Qiang Zhang
Keyword(s):  
Visual Acuity ◽  
Visual Perception ◽  
Large Scale ◽  
Dynamic Error ◽  
Smooth Transition ◽  
Evaluation Function ◽  
Static Error ◽  
Terrain Rendering ◽  
Quad Tree ◽  
Screen Space

The data structure is the form of quad-tree in this paper. The terrain node's LOD evaluation function is given through comprehensive considering the three factors which are the static error of the terrain block ,the screen space dynamic error and visual perception based on the premise of visual acuity. The smooth transition factor is used to eliminate the phenomenon of popping in the GPU vertex shader. The idea to join the skirts is used to eliminate cracks between terrain blocks. The experimental results show that the algorithm can reflect the terrain LOD levels through the fluctuant of terrain and the visual perception intensity so that the terrain has a better adaptability while increasing frame rates and rendering realistic.

Assessing Visual Perception in Heritage Sites with Visual Acuity

2020 ◽  
Vol 14 (1) ◽  
pp. 1-18
Author(s):  
Martina Polig ◽  
Despina G. Papacharalambous ◽  
Nikolas Bakirtzis ◽  
Sorin Hermon
Keyword(s):  
Visual Acuity ◽  
Visual Perception ◽  
Heritage Sites

scholarly journals Stereoscopic Vision and Testing Techniques – Review

2020 ◽  
Vol 4 (2) ◽  
Keyword(s):  
Visual Acuity ◽  
Visual Perception ◽  
Diagnostic Tests ◽  
Early Years ◽  
Stereoscopic Vision ◽  
Risk Of Injury ◽  
Field Of Vision ◽  
Quality Of Vision ◽  
Testing Techniques

Stereoscopic vision or stereopsis is the highest level of binocular vision. It is acquired in the early years of life and requires the “simultaneous perception” of each eye separately, as well as the “matching” of the two images during brain development. First of all, it gives man the visual perception of depth, but it also broadens his field of vision and increases his visual acuity. As anyone can easily understand it is especially useful in everyday life. It is not particularly well known, but the quality of vision at night is based on stereotypes. Finally, people who do not have stereoscopic vision are in a difficult position as they are at immediate risk of injury. For the above reasons, it is clear why constipation should be controlled, with specific diagnostic tests, especially during childhood.

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