33 results about "Near visual acuity" patented technology

A system and method for treating and preventing loss of visual acuity. The system comprises a vision correcting lens, such as a contact lens, having a material with a regular pattern of orientation of polarizable molecular bonds, so as to create a birefringent effect. Off-axis light rays are refracted through the contact lens so as to focus in front of the retina, whereas on-axis light rays pass through the contact lens without refraction, such that their focal point on the fovea is unaltered. In an exemplary embodiment, a contact lens of the present invention is capable of independently altering the refractive state of the eye in relation to fovea and peripheral retina so as to simultaneously correcting visual acuity while minimizing the signal for axial growth and hence myopic progression.

A method to generate an output image that improves observation of a target image viewed on a medium by an optical system is disclosed. The method includes receiving at least one target image by a processing system, receiving at least one parameter by the processing system, defining an error signal associated with the difference between calculated optical system observation of intermediate images and the at least one target image, minimizing the error signal, and generating an output image associated with the intermediate image having the minimized error.

The invention discloses a sclera lens with an open window and a concave bag. One open window or a plurality of annularly distributed open windows is/are arranged in an optical area of the sclera lens; two or more concave bags are arranged in the concave bag ring area on the rear surface of the optical area, and the concave bags are used for capturing bubbles near the window; wherein the open window is located radially outward of the concave bag annulus region and is not located in a transition region of the sclera lens, the transition region being configured to be located above an angular sclera edge of the eye when worn. The lens disclosed by the invention cannot be adsorbed to the cornea, can be comfortably worn within 12 hours and can maintain clear visual acuity.

Provided herein are devices, systems, methods, apparatuses, and computer program products for determining a visual acuity of a reader. The device includes a display adapted to present a first line of text to the reader and an input device adapted to receive signals corresponding to the first line of text. The device further includes a processor that is adapted to determine a reading score associated with the first line of text, generate an acuity parameter based on the reading score and the first readability vector, and determine the visual acuity of the reader based on the acuity parameter and a reference acuity parameter.

The invention discloses an eagle eye midbrain loop return inhibition mechanism-imitated unmanned target drone target detection method, which comprises the following steps of: 1, calibrating a camera,acquiring internal and external parameters of the camera, and correcting image distortion; 2, carrying out the illumination processing of imitating the color constancy of the beasts, and recovering the color information of the image under the normal illumination; 3, preprocessing an eagle midbrain opening and closing corresponding mechanism-imitated image; 4, extracting a salient region based on an eagle visual sensitivity function; and step 5, carrying out target output based on an eagle brain return inhibition mechanism. The method has the advantages that 1, an eagle eye biological image processing mechanism is used for reference, and an eagle midbrain loop return inhibition target detection framework is extracted and applied to small target detection of an unmanned target drone; 2, themethod can adapt to the small target detection problem of the target drone in various environments, the influence of external factors such as illumination and contrast is eliminated, and the algorithmadaptability is improved; and 3, the method is simple in framework, the target detection calculation amount is saved, and the airborne calculation load requirement is greatly reduced.

The invention relates to an objective, rapid and accurate visual acuityinspection system based on steady-state visual evoked potential, which comprises a stimulation normal form design module, an SSVEP signal acquisition, processing and feature recognition module, a spatial frequency gradient presentation module based on maximum likelihood estimation and a visual acuity judgment and feedback module. The gratings, checkerboard grids or concentric rings are used as visual stimulus paradigms, parameters such as time frequency and the like are preset, stimulation normal form spatial frequency parameters of each test are adaptively set through a maximum likelihood method according to a psychophysics visual acuity measurement function, so that accurate evaluation of visual acuity is completed within a short test time, and objective, rapid and accurate examination is provided for visual acuity in ophthalmic examination.

The invention discloses a method for determining the horizontal evacuation speed of old people in an evacuation model. The method comprises the following steps: acquiring basic characteristics of oldpeople, wherein the basic characteristics comprise visual acuity VA, sight line level height, evacuation speed V0 in a smokeless environment and minimum evacuation speed Vmin; determining an extinction coefficient Kc0 when the evacuation speed of the elderly begins to drop; determining an extinction coefficient Kc1 when the evacuation speed of the old people is reduced to the minimum value; carrying out fire simulation on a building needing fire evacuation simulation through PyroSim software to obtain an extinction coefficient of the sight line horizontal height H of the elderly at any momentof the building, and recording the extinction coefficient as Kc; comparing the Kc, the Kc0 and the Kc1, and then determining the horizontal evacuation speed V of the old people according to a formula.The horizontal evacuation speed, determined by the method, of the elderly in the fire is closer to the real evacuation speed of the elderly, and a scientific basis can be provided for escape management of elderly groups and making of emergency evacuation plans.

The Mobile Screening and Utility Unit (MSUU) serves as an additional, exposure-reducing, enclosed barrier for screeners. The MSUU reduces contracting any virus such as COVID-19 by person-to-person contact or aerosol means from symptomatic or asymptomatic patients while the screener is inside the unit. Key features are: reusable, wheel-based (used in/outside), and sanitized/disinfected using methods endorsed by the Centers for Disease Control and Prevention (thus reducing the need for expensive PPE). The unit front has a clear/transparent pane for visual acuity and two protective sleeves and pouch. The screener enters the unit from the rear, zips it shut, then moves forward to insert his or her arms through the sleeves and look through the pane. Screening is performed with minimal to no exposure to the screener. The screener can easily communicate without the use of additional audio equipment. Seated configurations are available that can be used with or without tables.

The invention discloses a visual assistance method for people with visual dysfunction. The method comprises the following steps: S1, providing AR glasses based on planar waveguide imaging; s2, detecting eye function parameters, including central visual acuity, contrast sensitivity, fusion function and stereoscopic vision, of a wearer by using AR glasses imaging; s3, the camera system tracks an observation target of the wearer, shooting is carried out after accurate positioning, and a target image is obtained; s4, performing optical amplification and background digital amplification on the obtained digital image information, performing feature enhancement according to the functional parameters of the eyes of the wearer, and outputting imaging light; and S5, imaging the imaging light in the retina of the wearer after the imaging light passes through the planar waveguide. Correspondingly, the invention further discloses a visual assistance system for people with visual dysfunction and the intelligent AR glasses. According to the invention, people with visual dysfunction can be helped to recover normal life, work and study, necessary scientific rehabilitation training can be carried out, and patients can be helped to develop and effectively use residual vision.

The invention discloses a visual prosthesis microelectrode array capable of generating converged virtual electrodes. The visual prosthesis microelectrode array comprises a microelectrode array, a common recovery electrode and a micro-current stimulator, wherein the micro-current stimulator stimulates adjacent ring electrodes in the microelectrode array according to a received external stimulationsignal; the microelectrode array is combined with the far-end common recovery electrode to generate virtual electrodes; the virtual electrodes move in a one-dimensional direction by adjusting the stimulation current proportion of two adjacent ring electrodes; and the virtual electrodes move in a two-dimensional region and converged virtual electrode stimulation is realized by adjusting the stimulation current proportion of four adjacent electrodes. According to the visual prosthesis microelectrode array, stimulation sites of the converged virtual electrodes can be adjusted, so that local virtual electrode stimulation of a retina is realized, the number of perception sites of a visual prosthesis implant is increased, and the perception visual sensitivity of the visual prosthesis implant isimproved. In addition, by disk electrodes, local physical electrode stimulation can further be realized, and the original physical electrode stimulation sites can be reserved while virtual electrode stimulation is carried out.