Abstract: An interactive fit tool and methodology which may be utilized by an eye care professional to improve the efficiency and final outcome in selecting a pair of contact lenses targeted towards a specific patient visual need in the treatment of presbyopia. The interactive fit tool comprises an application which includes images that would allow a patient to decide if he or she desires balanced visual acuity, near biased visual acuity, or distance biased visual acuity. In addition, the interactive fit tool comprises fit guide tables and performs the calculations for vertex distance and spherical equivalent.

Abstract: In one aspect, there is provided a handheld vision tester. In this particular embodiment, the handheld vision tester comprises a display, cursor control, and an interface port. The display delivers vision tests to a user. The user interacts with the vision tests by using the display and cursor control. The interface port allows for communication of results of the vision tests from the handheld tester to external devices.

Abstract: Unified vision testing and/or training kiosk may utilize display devices and input devices to administer a number of visual testing and/or training tasks to an individual. One or more display devices may provide desired resolution, geometry, and/or touch sensitivity. One or more input devices may receive inputs of different types from different positions relative to a display device. Methods of visual testing and/or training may utilize the one or more display devices, one or more input devices, and/or other types of equipment to evaluate and/or improve the visual abilities of an individual.

Abstract: A system for treating amblyopia through the visual stimulation of the brain through a predetermined regime is provided. The system for treating amblyopia comprises a headmountable visual content display device, a controller unit, a visual content source, a data storage device, a graphic processing unit and an audio source. A protocol useful for treating amblyopia by visual stimulation of the brain is also provided. A predetermined regime useful for treating amblyopia by stimulation of the brain is additionally provided.

Abstract: The invention is directed to quantification of the effects of drugs on a patient using pupillometric measures. Apparatus and processes for obtaining control and patient measures and deriving relationships from same are provided. The methods of the invention provide doctor quantitative feedback on patient symptoms and on the effects of a drug or dosage of same on a patient, as well as provide assessment capability to patients and law enforcement.

Abstract: Systems and methods are provided for presenting three-dimensional content on a display. An exemplary system for presenting a plurality of frames on a display comprises a first lens, a second lens, and an activation system. The activation system utilizes electromagnetic radiation to activate the first lens when a respective frame being presented on the display corresponds to the first lens, resulting in the first lens being substantially transparent and the second lens being substantially opaque, and to activate the second lens when a respective frame being presented on the display corresponds to the second lens, resulting in the second lens being substantially transparent and the first lens being substantially opaque.

Abstract: Disclosed is a method for detecting neovascularized tissue that includes placing a tissue in the path of a light beam, measuring a polarization shift of the light beam, and detecting neovascularized tissue if the measured polarization shift corresponds to a polarization shift of a neovascularized tissue. Also disclosed is an apparatus for detecting neovascularized tissue that includes a laser, a polarizer coupled to the laser, a tissue sample holder coupled to the polarizer, an analyzer coupled to the tissue sample holder, a detector coupled to the analyzer, and a data acquisition system coupled to the detector, wherein the data acquisition system is configured to measure a polarization shift of a light beam emitted by the laser and diagnose an ocular disease if the measured polarization shift corresponds to a polarization shift of a neovascularized tissue.

Abstract: The disclosure describes an apparatus (100) for improving a visual function, having a first display element (1) for displaying at least one moving grid (110) consisting of grid elements (120); at least one portable closure element (2) for the occlusion of at least one eye; a portable eye tracking device (3) for measuring at least one characteristic value of a non-occluded eye; a first control unit (5) having a first communication interface (140) to the eye tracking device (3) and a second communication interface (150) to the at least one closure element (2); and a second control unit (6) connected to the display element (1), with a third communication interface (160) to the first control unit (5).

Abstract: Systems and methods for improving the peripheral vision of a subject are disclosed. In one aspect, embodiments of the present disclosure includes a method, which may be embodied on a system, for improving peripheral vision of a subject using a visual marker on a display screen, the method includes, displaying a peripheral target on the display screen, the peripheral target having a visually discernable characteristic and determining whether the subject is able to correctly identify the peripheral target displayed on the display screen using the peripheral vision. The visual marker is intended for viewing using central vision of the subject and the peripheral target is intended for identification using the peripheral vision of the subject.

Abstract: An ophthalmological device, comprising an eye patch, a photovoltaic, and a battery, wherein said photovoltaic is interconnected to said battery.

Abstract: A portable electronic apparatus has a portable electronic device, a lens assembly, a control unit and a display module. The portable electronic device has a shell with a chamber and an opening communicating with the chamber. The lens assembly is mounted in the opening of the shell. The display module is mounted in the chamber of the shell. The control unit is mounted in the portable electronic device to control the display module to project various object images into a user's eyes. The user can exercise the eyes by releasing the eye muscles, tightening the eye muscles, rolling the eyes upwards, downwards, leftwards, rightwards, or rolling the eyes circularly when the user looks at the projected object images. Vision defects, such as myopia and astigmatism, can be relieved.

Abstract: Systems and methods for improving the peripheral vision of a subject are disclosed. In one aspect, embodiments of the present disclosure includes a method, which may be embodied on a system, for improving peripheral vision of a subject using a visual marker on a display screen, the method includes, displaying a peripheral target on the display screen, the peripheral target having a visually discernable characteristic and determining whether the subject is able to correctly identify the peripheral target displayed on the display screen using the peripheral vision. The visual marker is intended for viewing using central vision of the subject and the peripheral target is intended for identification using the peripheral vision of the subject.

Abstract: Cognitive deficits involving attention, sequential processing, reading, speed of processing, and navigation may be diagnosed and remediated in a subject by respectively measuring and improving contrast sensitivity for motion discrimination of the subject. A background may be displayed with a contrast and temporal frequency and either single, or multiple, higher spatial frequencies that may repeat over a wider area than the individual frequency components. A test window may be superimposed over the background, and includes a test pattern with a contrast and a spatial frequency and a temporal frequency. The subject may provide a signal indicative of the direction the subject believes the test pattern moved. In response to this signal, the contrast of the test pattern, the spatial frequency of the background, the spatial frequency of the test pattern, or the temporal frequency may be modified, either by increasing or decreasing its respective value.

Abstract: The vision protection method and system thereof is provided to ensure a viewer to rest his/her eyes after viewing on an electronic device for a certain period, wherein the eyesight protection method includes the steps of detecting one of more working parameters of the viewer in responsive to a preset working threshold in a working mode of the electronic device during the viewer is working on a current work displaying by the electronic device; switching the working mode of the electronic device to a resting mode; and switching the electronic device from the resting mode back to the working mode to resume the display of the current work of the electronic device. Therefore, the viewer is enforced to rest his/her eyes after every certain period.

Abstract: Systems and methods are disclosed for evaluating human eye tracking. One method includes receiving data representing the location of and/or information tracked by an individual's eye or eyes before, during, or after the individual performs a task; identifying a temporal phase or a biomechanical phase of the task performed by the individual; identifying a visual cue in the identified temporal phase or biomechanical phase; and scoring the tracking of the individual's eye or eyes by comparing the data to the visual cue.

Abstract: Systems and methods are provided for altering the position or visual appearance of a movable indicator in a GUI that is controlled by eye tracking to counteract a perceptual fading of the movable indicator with respect to the GUI. The position of the user's point of gaze may be tracked, the movable indicator may be rendering at a position associated with the user's point of gaze, and the position or visual appearance of the movable indicator may be altered when an event, such as a passage of time or a blinking of the user's eyes, is detected.

Abstract: The invention relates to a stereovision optometry apparatus comprising: a 3D display unit for displaying 3D image; a reference 2D display unit for displaying reference 2D image; an eyepiece in opposite side of the 2D display unit configured to view the images; a reflective mirror in opposite side of the 3D display unit configured to move toward and away from the 3D display unit; and a half mirror arranged between the 3D display and the reflective mirror and disposed at a point where propagation paths of the 2D image and the 3D image intersect; wherein the 2D image penetrates through the half mirror to reach the eyepiece; wherein the 3D image penetrates the half mirror to be reflected on the reflective mirror and then the reflected image is reflected on the half mirror to reach the eyepiece.

Abstract: An electronic vision-therapy apparatus includes a frame, a lens module and a control unit. The lens module includes first and second liquid crystal lenses. The control unit is for controlling the first and second liquid crystal lenses to cooperatively generate and display a light filtering pattern. The light filtering pattern has an opaque part and a plurality of transparent parts. The control unit configures a part of the first liquid crystal lens that corresponds to the opaque part to allow only light having a first polarization to pass therethrough, and configures a part of the second liquid crystal lens that corresponds to the opaque part to allow only light having a second polarization orthogonal to the first polarization to pass therethrough.

Abstract: The invention relates to an instrument for simulation of multifocal ophthalmic corrections, comprising two optical channels with different optical power values in the beams coming from the object observed, wherein at least one channel comprises a Badal system. This instrument simultaneously provides images of objects near and far focused. The system provides the same optical magnifications for each channel, regardless of the optical power thereof, and produces superimposed retinal images with different degrees of focus which, unlike other devices, are all of the same size. The instrument allows simulating different optical powers for near vision and different refractive corrections for distant vision.

Abstract: Systems and methods are disclosed for evaluating human eye tracking. One method includes receiving data representing the location of and/or information tracked by an individual's eye or eyes before, during, or after the individual performs a task; identifying a temporal phase or a biomechanical phase of the task performed by the individual; identifying a visual cue in the identified temporal phase or biomechanical phase; and scoring the tracking of the individual's eye or eyes by comparing the data to the visual cue.

Abstract: The present invention relates to an apparatus and method for the assessment and rehabilitation of vision impairment. In particular, the invention is concerned with an apparatus displaying visual stimuli and the method of using this device for the purpose of assessment and rehabilitation of individuals with acquired brain injury and visual impairment resulting therefrom. The apparatus comprises a display means with a plurality of visual stimuli switched on and off in predetermined sequences. The sequences are adapted to be used to assess and rehabilitate a person's visual impairment.

Abstract: The invention relates to a device for rehabilitating and/or causing binocular motivity through sensory stimulation of a patient, said device including a planar stand (10) that is defined by a longitudinal axis of symmetry (AA?), the stand (10) including a plurality of means for transmitting at least one sensory stimulus, said transmission means including means for viewing a visual stimulus (101-136) and means for transmitting an auditory stimulus adjacent to the means for viewing a visual stimulus. The transmission means are evenly arranged along isovergence arcs (201-204) that are placed along the stand (10). Said device moreover includes a control system (20) that is at least intended for controlling the transmission of said at least one sensory stimulus (101-136).

Abstract: A visual therapy system is provided that includes a computer, a projector, a display, and input devices, including a head sensor remote, a sensor bar, a balance board, hand controlled remote, and a head sensor. The system uses an interactive interface and blue tooth software that combines remotes, an interactive balance board and infra-red head sensors. The system provides specialized therapy modules which may be based on the concept of Top Down Processing and may be designed to enhance ocular motor control, visuomotor and binocular performance while integrating vision, auditory, proprioception, balance and visuomotor control.

Abstract: Graphical first individual interfaces, systems and methods of implementing an adaptable, interactive educational tool that provides cognitive and social benefits. An embodiment can be configured to provide a graphical first individual interface for presenting text and related content associated with a predetermined general subject matter. The specific text and related content presented to the first individual may be determined after baseline tests and related use are recorded to calculate the first individual's cognitive wellness. The present invention also provides social benefit by integrating a first individual's social network for uses in communication with the first individual's social network and in recalling the first individual's social network. The present invention further includes a unique algorithm for personalizing information and methodologies of implementing and displaying the educational tool to a first individual thereof.

Abstract: System and methods for testing and/or training a subject's visual ability are provided. More specifically, the method may include testing various aspects of the subject's visual acuity, such as clarity, contrast, tracking, etc. By using various tests, a more efficient examination may be administered. In accordance with the invention, an individual may be tested using methods of testing and/or training at a unitary center, where the unitary center is capable of presenting visual tests to the individual, receiving input from the individual, and processing the received input. Such a unitary test center may further be configurable, so that the tests administered may vary based on the needs of the individual. The received input may then, for example, be used to compute data related to the user's visual acuity, both overall and for each individual test.

Abstract: A method for treating a weak viewer-eye includes the steps of receiving eye-strength data indicative of an eye-strength of the weak viewer-eye and causing a 3D display system to vary, in accordance with the eye-strength of the weak viewer-eye, display characteristics of a perspective that the 3D display system displays.

Abstract: A binocular viewer, a method of measuring and training vision that uses a binocular viewer and a vision measurement and training system that employs a computer to control the binocular viewer. In one embodiment, the binocular viewer has left and right display elements and comprises: (1) a variable focal depth optical subsystem located in an optical path between the display elements and a user when the user uses the binocular viewer and (2) a control input coupled to the left and right display elements and the variable focal depth optical subsystem and configured to receive control signals operable to place images on the left and right display elements and vary a focal depth of the variable focal depth optical subsystem. In another embodiment, the binocular viewer lacks the variable focal depth optical subsystem, but the images include at least one feature unique to one of the left and right display elements.

Abstract: An apparatus and method are disclosed that provide for establishing and/or improving binocular vision by adaptation of perceptual motor learning for the visual system of a patient suffering of a binocular vision disorder. The apparatus has a set of two units, one for respectively eye, for manipulation of a vision parameter of the visual presentation, e.g. picture, movie, image. To control the visual presentation on respectively unit a processing unit is connected. The processing unit is adapted to determine a boundary value of a first and/or second vision parameter for the first and/or second manipulation of the first and second unit, where binocular vision disappears for the patient. Furthermore, the processing unit controls at least one vision parameter by manipulating, including oscillating or fluctuating, it within a first range, the first range having a maximum value that is less than the boundary value, for the perceptual motor learning.

Abstract: A method and associated aid for training visual skills associated with a selected activity. The method is grounded upon a theory which involves a first concept referred to as a “planes of reference box” and a second concept referred to as a “momentum triangle”. The method involves mounting to a head of a wearer a transparent viewing surface through which the wearer observes his or her environment. The transparent viewing surface has activity specific balance reference indicia from the planes of reference box and activity specific momentum reference indicia from the momentum triangle.

Abstract: An apparatus for measuring eye movement (ocular pursuit) of a subject by moving a target along an arcuate member disposed ahead of the subject is described, wherein the target is moved in a channel formed in the arcuate member, and a clamp adapted for moving with the target for locating the position of the target along the arcuate member, thereby reducing unintended further movement thereof once the measurement has been completed.

Abstract: Systems and methods may test and/or train the peripheral visual abilities of an individual. Peripheral visual abilities may be tested and/or trained while maintaining a central visual focus by the individual. A central display element may display central visual indicia, while a peripheral display element may display peripheral visual indicia. Each visual indicia displayed may possess one or more trait and, optionally, one or more property. Inputs may be received at a central input device and/or a peripheral input device, with inputs corresponding to the traits perceived to be possessed by displayed indicia. By determining the correspondence of received inputs to the traits possessed by corresponding indicia, the peripheral visual abilities of an individual may be tested and/or trained in accordance with the present invention.

Abstract: A vision exercising apparatus including a visual display device (1); a locating means (5) for locating the head of a user at a position to provide a substantially known relationship between the visual display device (1) and the field of view of the user; display position control means for actuating the visual display device (1) to display a predetermined pattern at a known display position which corresponds to a specific viewing area of the field of view of the user; user actuable response means (17) to enable a user response to be provided; further control means to control the display position control means to repeatedly display the predetermined pattern at the known display condition; and means to collate user response and to evaluate the statistical significance of the user response for that display position. A predetermined pattern can thus be displayed in the field of view of a user that requires exercising.

Abstract: An embodiment of the disclosure consists of a rectangular lightweight rigid handled frame, four adjustable telescoping foldout locking legs with protective feet, a rear-facing mirror, a pair of forward-facing mirrors, an eleven-light light source, and a control panel. The rear-facing mirror is connected to the frame and is adjustable about a horizontal axis to form a vertical angle in order to facilitate the reflections from the light source back and forth between the rear-facing mirror and the pair of forward-facing mirrors. The pair of forward-facing mirrors are connected to the frame, are spaced apart to form the porthole, and are adjustable on both a vertical and horizontal axis in order to form the vertical angle and the rotational angle needed to facilitate the reflections from the light source back and forth between the rear-facing mirror and at least one of the pair of forward-facing mirrors.

Abstract: A binocular viewer, a method of measuring and training vision that uses a binocular viewer and a vision measurement and training system that employs a computer to control the binocular viewer. In one embodiment, the binocular viewer has left and right display elements and comprises: (1) a variable focal depth optical subsystem located in an optical path between the display elements and a user when the user uses the binocular viewer and (2) a control input coupled to the left and right display elements and the variable focal depth optical subsystem and configured to receive control signals operable to place images on the left and right display elements and vary a focal depth of the variable focal depth optical subsystem. In another embodiment, the binocular viewer lacks the variable focal depth optical subsystem, but the images include at least one feature unique to one of the left and right display elements.

Abstract: The present invention concerns a method and device for the training of human vision. In particular, the invention involves the use of multimodal stimulation and principles of biofeedback to aid in the detection of visual targets. The intended population to benefit from this device are those who have experienced stroke or compromise to areas of the visual system responsible for conscious sight. Such patients may show either visual inattention or partial to complete blindness in both eyes. Biofeedback is also used to assist in training of sight.

Abstract: Systems and methods for improving the peripheral vision of a subject are disclosed. In one aspect, embodiments of the present disclosure includes a method, which may be embodied on a system, for improving peripheral vision of a subject using a visual marker on a display screen, the method includes, displaying a peripheral target on the display screen, the peripheral target having a visually discernible characteristic and determining whether the subject is able to correctly identify the peripheral target displayed on the display screen using the peripheral vision. The visual marker is intended for viewing using central vision of the subject and the peripheral target is intended for identification using the peripheral vision of the subject.

Abstract: A learning-based visual attention prediction method is disclosed. The method includes a correlation relationship between the fixation density and at least one feature information being learned by training, followed by a test video sequence of test frames being received. Afterward, at least one tested feature map is generated for each test frame based on the feature information. Finally, the tested feature map is mapped into a saliency map, which indicates the fixation strength of the corresponding test frame, according to the correlation relationship.

Abstract: One aspect of the invention provides a method for training a classification algorithm to detect a retinal pathology. The method includes: for a plurality of pseudo two-dimensional data sets of one-dimensional data points, each pseudo two-dimensional data point representing RNFL thickness values for a subject and corresponding index values for the data points: performing fractal analysis on the data set to calculate a plurality of fractal dimensions and calculating a plurality of slopes between each fractal dimension; combining the plurality of slopes for subjects labeled as pathologic into a pathologic data set; combining the plurality of slopes for subjects labeled as healthy into a healthy data set; and applying a linear discriminant function the pathologic data set and the healthy data set; thereby training a classification algorithm to detect the retinal pathology.

Abstract: The visual focusing and/or vergence abilities of a subject may be trained and/or tested using apparatuses and methods in accordance with the present invention. The subject may be provided with an apparatus having optical elements having different optical characteristics and instructed to look through an optical element having a first optical characteristic and to focus on an indicia or object. The subject may be instructed to rotate the apparatus and to look through optical elements having a second optical characteristic and to focus on the same or different indicia or object. The subject may be instructed to repeat this process with this or further apparatuses having optical elements having the same or different optical characteristics. The visual focusing and/or vergence abilities of a subject may thus be tested and/or trained.

Abstract: A system for treating binocular anomalies. The system includes one or more imaging devices, one or more visual displays, and a computing device. The imaging devices may include right and left imaging devices that capture images of a patient's right and left eyes, respectively. The displays may include right and left displays that provide right and left visual stimulation, respectively. The computing device identifies right and left locations on the right and left retinas, respectively, based at least in part on images of right and left eyes, respectively. The brain fuses images positioned at the right and left locations on the retinas into a single image. The computing device transmits right and left positioning signals to the right and left displays, respectively, that indicate that the right and left visual stimulation, respectively, are to be displayed so they are positioned at the right and left locations, respectively, on the retinas.

Abstract: Systems and methods for improving the peripheral vision of a subject are disclosed. In one aspect, embodiments of the present disclosure includes a method, which may be embodied on a system, for improving peripheral vision of a subject using a visual marker on a display screen, the method includes, displaying a peripheral target on the display screen, the peripheral target having a visually discernable characteristic and determining whether the subject is able to correctly identify the peripheral target displayed on the display screen using the peripheral vision. The visual marker is intended for viewing using central vision of the subject and the peripheral target is intended for identification using the peripheral vision of the subject.

Abstract: The contrast sensitivity of an individual may be tested and/or trained using a plurality of circular contrast zones. The individual may select the circular contrast zone having a different degree of contrast than the other circular contrast zones. For example, the individual may select the circular contrast zone having the highest or lowest contrast of a displayed plurality of circular contrast zones. A plurality of circular contrast zones may be displayed with a spatial arrangement that facilitates inputting a selection of one of the plurality by the individual. A variety of input devices may be used to receive a selection from an individual. Both the accuracy and speed of an individual's contrast sensitivity may be tested and/or trained in accordance with the present invention.

Abstract: Systems and methods for improving the peripheral vision of a subject are disclosed. In one aspect, embodiments of the present disclosure includes a method, which may be embodied on a system, for improving peripheral vision of a subject using a visual marker on a display screen, the method includes, displaying a peripheral target on the display screen, the peripheral target having a visually discernable characteristic and determining whether the subject is able to correctly identify the peripheral target displayed on the display screen using the peripheral vision. The visual marker is intended for viewing using central vision of the subject and the peripheral target is intended for identification using the peripheral vision of the subject.

Abstract: An artificial eye model for use in ophthalmological measurements exhibits a simulation of at least one eye structure, for instance of a cornea or of a crystalline lens. In accordance with the invention the simulation possesses fluorescent properties. In this way, a beam expansion as a result of multiple scattering in the case of scattered-light-based photographic recordings can be avoided. Instead of this, a sharp-contour imaging of the simulated eye structures is made possible.

Abstract: The present invention provides a new method and system for preventing myopia acquisition in children and young adults. There is strong evidence that near work might lead to myopia. The axial length of a human eye is growing in the first 25 years of life. There is experimental evidence for feed-back loops to control this growth. Prolonged near-work might interfere with these feed-back loops in a way that the axial length growth accelerates to provide perfect near vision—myopia. Using reading glasses in normal-sighted children and young adults prevents interference of prolonged near-work with axial length growth, hence preventing environmentally driven myopia acquisition.

Abstract: System and methods for testing and/or training a subject's vision and coordination abilities are provided. More specifically, the method may include testing various aspects of the subject's vision and coordination abilities, such as eye-hand coordination, split attention, reaction time, body coordination, etc. By using various tests, an efficient examination may be administered. In accordance with the invention, an individual may be subjected to such a method of testing and/or training at a unitary center capable of presenting such tests to the individual, receiving input from the individual, and processing the received input. Such a unitary test center may further be configurable, so that the tests administered may vary based on the needs of the individual. The received input may then, for example, be used to compute data related to the user's vision and coordination abilities, both overall and for each individual test.

Abstract: A device for accommodation training includes a primary light and a sensor supported by a housing and configured to be worn atop the head of the user to capture light reflected by the retina. One or more alignment lights may be provided, along with mounts for adjusting the positioning of the lights and sensor. A feedback signal such as an audible tone is produced as a function of the detected light, providing confirmation to the user that a desired control over the ciliary muscle has been achieved.

Abstract: The present invention tests and/or trains the visual sensitivity of a subject using adaptable visual indicia. One or more visual indicia possessing a visual trait are displayed to the subject. The displayed visual indicia possessing a visual trait may be adjusted to determine when a subject can and cannot be perceived by the subject. A displayed visual indicia may be adjusted in its size, rate of movement, direction of movement, location of display, duration of display, or other characteristic. To determine whether a subject correctly perceived the visual trait possessed by a displayed visual indicia, an input may be received from the subject. If an input received corresponds to the visual trait possessed by the displayed visual indicia, the subject may be determined to have correctly perceived the displayed visual indicia and the visual trait.

Abstract: Systems, methods, and apparatuses for amblyopia and ocular deviation correction are disclosed. In one aspect, embodiments of the present disclosure include a system for amblyopia correction, the system includes, an image processing unit to identify a set of image parameters and, when, in operation, the image processing unit modifies a source visual content based on one or more of the set of image parameters to generate visual content and a visualization unit coupled to the image processing unit operable to receive visual content from the image processing unit, the visualization unit having a screen, when, in operation, the screen displays the visual content.

Abstract: Systems, methods, and apparatuses for amblyopia and ocular deviation correction, as well as visual interfaces, are disclosed. In one aspect, embodiments of the present disclosure include a system for amblyopia correction, the system includes, an image processing unit to identify a set of image parameters and, when, in operation, the image processing unit modifies a source visual content based on one or more of the set of image parameters to generate visual content and a visualization unit coupled to the image processing unit operable to receive visual content from the image processing unit, the visualization unit having a screen, when, in operation, the screen displays the visual content.