30 results about "Visual acuity testing" patented technology

The above objects are achieved with a compact neuro-otologic testing device and method of utilizing the same according to the present invention. The device according to the present invention provides an image producing laser with a right hand, servo controlled galvanometric based XY interface. The high quality closed loop servo control system that can drive the target (i.e. the laser image) in excess of 1,000,000 degrees / second2 and at velocities in excess of 12000 degrees / second. The bandwidth of the XY interface is greater than 400 Hz, providing high image reproducibility. The repeatability and position accuracy of the target is +−3 arc-seconds and the field of range of the XY interface are about 60 degrees (i.e. about 60 degrees horizontal and 60 degrees vertical).

An aberrometer is provided for automatically measuring a human eye aberration, determining a subjective visual acuity associated with the selection of a best spherocylindrical correction, and investigating the influence of high orders aberrations on the visual acuity. The aberrometer includes a point light source which is projected on the eye retina, scattered back by the retina, and passes through the eye optical systems acquiring a phase modulation corresponding to the total eye optical aberration. The aberrometer also includes a wave front sensor whose output signal is transmitted to a device control system, an aberration compensation system which is disposed between the human eye and the wave front sensor and through which radiation coming out from the eye and projected on the eye retina passes, and a test picture projector which projects the test picture image on the eye retina through the aberration compensation system.

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.

A subjective vision tester includes a pair of right and left lens chamber units (2) each having a test window (4), a first lens disk (11-14) provided with an aperture and a plurality of optical elements (110, 120, 130, 140) and placed in a position closer to an examinee's eye (E) within the each lens chamber unit, and a second lens disk (15, 16) provided with an aperture (151, 161) and a plurality of optical elements (150, 160) and placed in a position farther from the examinee's eye than the first lens disk within the lens chamber unit. The first lens disk and the second lens disk are equal in diameter. The diameter of the diameter of the aperture in the second lens disk is larger than each optical element in the first lens disk.

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.

The invention provides a method for regulating the sighting mark moving speed in a dynamic visual acuity testing system. By adopting the method, the sighting mark moving speed can be arbitrarily regulated, and the qualification degree of a driver on a specific task can be truly reflected. The method comprises the following steps: (1) starting; (2) acquiring a sighting mark moving speed v; (3) acquiring the distance d between a tested person and the sighting mark; (4) calculating a sighting mark actual moving speed v1 according to a formula (1); (5) acquiring a single pixel width s and a sighting mark generation frequency f of a display screen; (6) calculating a pixel per inch u of a sighting mark in the adjacent frame moving on the display screen according to a formula (2); and (7) finishing.

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 a virtual eyepiece device for monitoring eyeball movement. The virtual eyepiece device comprises an eyepiece frame which is internally provided with a lens assembly, two human eye testing areas, a micro display, a camera assembly and a data transmission assembly; the lens assembly is composed of two lens sets which are arranged in a left and right mode; the micro display is located at the back of the lens assembly, and the human eye testing areas are correspondingly arranged in front of the lens assembly in a left and right mode; the camera assembly comprises two camera components which face the two human eye testing areas respectively; the data transmission assembly connects the micro display and the camera assembly with a computer respectively. According to the virtual eyepiece device, by mean of combination of a virtual imaging eyepiece and computer software, interference of the outside world to the testing process is reduced, dynamic visual acuity testing is standardized, reliable eyeball movement feature data can be obtained, and a scientific basis is provided for subsequent dynamic visual acuity feature evaluation.

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.

Disclosed is a centesimal visual acuity chart. The centesimal visual acuity chart is characterized in that a centesimal system is adopted to express visual acuity, so that the better the visual acuity is, the higher the score. Each visual target of the visual acuity chart is in the shape of a notched ring, a notch is fan-shaped, a circle center angle is 12.76 degrees, width of the ring is equal to that of the middle of the notch, outer diameter of the ring is 10 times of width of the ring while inner diameter of the same is 8 times of width of the ring, size of the visual targets is in continuous gradient changing, and a vision score difference of each gradient is 10 scores.100 scores is for a test of 5 m, the width of the middle of the notch is 1.454 mm, the visual target of 100 scores is taken as a base point, the size of the visual targets of 90 scores and lower scores is sequentially increased progressively outward by 1.25 times, and the size of the visual targets of 110 scores and higher scores is sequentially decreased progressively inward by 0.8 time. The visual targets can sleeved and overlapped at intervals according to size order to form four groups to be combined into the visual acuity chart, and size of the visual acuity chart is reduced. The visual acuity chart can be made into an electronic product, namely a visual acuity tester, by using a led semitic form to increase interestingness when visual acuity of children is tested.

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.

A system for replicating a standardized visual acuity test, such as the 20′ Snellen test may comprise a binocular viewer attached to a smartphone. A binocular viewer may comprise a housing comprising a pair tube covers having voids allowing for viewing through a pair of lens tubes with each lens tube in visual communication with a second lens a first lens an aperture and a front cover. The optical systems use an artful combination of front and back lens surfaces, demagnification and other systems to faithfully replicate the sight lines perceived by a user of a traditional 20′ test. The system also allows for the incorporation of other tests conducted with both eyes including Color Sensitivity and Contrast, furthermore by placing a deformable, tunable lens between the second lens and the eye the device serves as an ophthalmic refractometer, allowing a Spherical Equivalent refraction estimate for each eye.

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.