30 results about "Visual acuity testing" patented technology

When a Landolt ring optotype is presented in a visual acuity testing unit, an examinee answers a position of a slit of the optotype through an operation of a joystick lever or the like. If an examinee gives a right answer within a standard time at a first presentation of optotype, examination at a higher visual acuity grade is executed by presenting a smaller Landolt ring optotype. In case of a right answer over the standard time, reexamination at the same visual acuity grade is executed twice at the most. If a right answer is given at least once, examination at a higher visual acuity grade is executed. In case of a wrong answer within the standard time at a first presentation of optotype, reexamination at the same visual acuity is executed only once. If the right answer is given at this reexamination, examination at a higher visual acuity grade is executed. Reexamination is thus executed, so that the result of the examination is correct. In addition, the examination time can be shortened since necessary number of times of reexaminations is minimum.

A visual acuity examination is performed on a patient by bringing a confocal imaging apparatus up to a patient's eye. Stimuli at various points in the patient's field of view are generated while the patient fixates on a point. The patient's responses to the stimuli are recorded with the movement of the eye with is tracked with the aid of the confocal imaging apparatus. The position of said stimuli on the retina is corrected to take into account any movement of the eye between stimuli.

Eye chart for testing visual acuity which includes a plurality of optotypes arranged in a plurality of lines with each optotype in a line having a uniform resolution throughout and the resolution for each optotype in a given line is the same. The optotypes are generated by standardizing the maximum resolution angle any one letter may have and such is done by utilization of a design circle which represents the maximum resolution.

Disclosed herein are system and method for testing and analysis of visual acuity and changes using an acuity model, the acuity model generated based on one or more acuity chart design parameters and candidate acuity parameters calculated using the acuity test data of the subject, the acuity model comprising a chart-specific psychometric function determined using a family of multiple-optotype psychometric functions, and wherein the acuity model is configurable to estimate possibility of obtaining the acuity test data of the subject.

A visual acuity testing apparatus includes a target presenting unit for displaying various targets to be presented to a subject's eye, an optical element arranging device for retaining various optical elements, and selectively arranging the optical element corresponding to a response from the subject between the subject's eye and the target presenting unit, an operation section which is operated for selecting each of targets and each of the optical elements, a display section for displaying an operation image illustrating an operation content of the operation section, a memory for storing a plurality of target data illustrating each of the targets and operation image data illustrating the operation image, an arithmetic control section for extracting the target data and the operation image data from the memory according to an operation of the operation section, and an image output section having at least two output ports.

Disclosed herein are system and method for testing and analysis of visual acuity and changes using an acuity model, the acuity model generated based on one or more acuity chart design parameters and candidate acuity parameters calculated using the acuity test data of the subject, the acuity model comprising a chart-specific psychometric function determined using a family of multiple-optotype psychometric functions, and wherein the acuity model is configurable to estimate possibility of obtaining the acuity test data of the subject.

The invention relates to an automatic regulation vision examination device for the ophtalmology department, and belongs to the technical field of medical instruments. The automatic regulation vision examination device for the ophtalmology department comprises an information processor main body, wherein a display table is arranged on the upper side of the information processor main body; an imaging tube is arranged on the display table; a control panel is arranged on the front side of the display table; a main power button disk is arranged on the upper side of the control panel; a main power button is arranged on the main power button disk; an instrument power regulation knob disk is arranged on the right side of the main power button disk; an instrument power regulation knob is arranged on the instrument power regulation knob disk; a patient seat connection plate is arranged on the right side of the information processor main body; a patient seat bracket is arranged on the upper side of the patient seat connection plate; and a patient seat is arranged on the upper side of the patient seat bracket. The automatic regulation vision examination device is complete in function and convenient to use, and is safe and efficient when used for testing vision of a patient, so that the workload of medical staff is relieved.

The invention relates to a heterogeneous vision chart and a method for visual acuity testing. The heterogeneous vision chart is a misaligned view composed of a heterogeneous reference area and at least two types of optotypes of different sizes. The heterogeneous reference area can lead to different vision Misjudgment of the size of an optotype of different sizes, visually thinking that a smaller optotype is not smaller than another larger optotype. The visual acuity test method judges whether the visual acuity of the inspected person is real visual acuity by checking the visual acuity difference of the heterogeneous visual acuity chart and the standard logarithmic visual acuity chart respectively. The present invention uses optical illusions of different sizes and perspective diagrams as an eye chart, which interferes with the judgment of object size by causing the illusion of visual depth without affecting the identification of real vision, thereby distinguishing fake vision.

The invention discloses an automatic assessment system for a visual cognition behavior function of a rodent. The automatic assessment system comprises a shape sensory ability testing unit, a visual acuity testing unit and a photoreception ability testing unit, wherein the adjacent units are mutually engaged through a transition chamber respectively; the shape sensory ability testing unit is composed of at least three channels which are arranged side by side and are different in inlet shapes; the visual acuity testing unit is composed of a chamber body and a plurality of clapboards, the chamber body is provided with an inlet and an outlet, the plurality of clapboards are arranged in the chamber body at interval, the bottoms of the adjacent clapboards are staggered and provided with passageways, and each clapboard, side walls and floor are printed with texture patterns with different spatial resolutions respectively; and the photoreception ability testing unit is composed of at least three channels which are arranged side by side and are different in lumen illuminance. The automatic assessment system disclosed by the invention has the advantages that a set of complete test system which has no adverse influences on experimental animals is designed to realize the reliable assessment of the visual cognition behavior function of the rodent so as to establish complete and reliable assessment indexes.