Eye-controlled interactive visual feedback evaluation method considering asthenopia

Abstract

The invention discloses an eye-control interactive visual feedback evaluation method considering asthenopia, and belongs to the field of man-machine interaction and human factor engineering. The eye-control interaction visual feedback evaluation method is constructed for the key positioning stage and selection stage in the eye-control interaction process, the problem of visual fatigue caused by eye-control interaction is considered, positioning and selection tasks are played through mobile equipment, the positioning task is completed through a cross mark and a round mark, and the eye-control interaction visual feedback evaluation method is established. Completing a selection task by using a delay selection mechanism and a sub-selection reconfirmation mechanism; collecting eye movement data when the user finishes the positioning task and selects the task by using different visual feedbacks by adopting eye control interaction equipment, and calculating a positioning error and a selection accuracy rate; visual fatigue occurrence time is considered, and subjective load and evaluation of the user are combined to carry out eye control interaction visual feedback evaluation; when the eye-controlled interaction is used for man-machine interaction, the visual feedback is preferentially selected according to the eye-controlled interaction visual feedback evaluation result, and the visual fatigue is reduced and the accuracy of the eye-controlled interaction is ensured according to the preferentially selected visual feedback.

Description

Technical Field

[0001] The present invention relates to an eye control interaction visual feedback evaluation method considering visual fatigue, belonging to the fields of human-computer interaction and human factors engineering. Background Art

[0002] Traditional human-computer interaction mainly relies on the use of keyboards and mice. To meet the ever-changing demands for interaction methods, more interaction methods have been developed, such as touch screen interaction, voice recognition, gesture control, and so on. However, with the pursuit of intelligent and natural interaction methods by people, traditional interaction methods have gradually shown their limitations and cannot fully meet the needs of users. These interaction methods require users to adapt to and learn specific operation methods, with relatively high learning costs, slow interaction speeds, often relying on system recognition and response, and traditional interaction methods occupy multiple human information processing channels and can only handle single-line tasks.

[0003] Eye control interaction, as an advanced interaction method, has unique advantages. Vision belongs to the first stage of human information processing, so eye control interaction has natural naturality. Users do not need to learn complex operation techniques additionally and can complete the interaction simply by looking at the screen, making the interaction process more natural, smooth, and direct, and greatly improving the interaction efficiency. Eye control interaction is a non-contact interaction method that does not require users to physically contact the device, which not only increases the convenience of interaction but also provides more interaction possibilities for disabled people and those with limited limb movement. Eye control interaction has the ability of parallel processing, and users can perform other tasks while conducting eye control interaction, thus improving work efficiency.

[0004] In the process of eye control interaction, visual feedback plays a crucial role. Visual feedback can not only help users accurately grasp the current state and process of the interaction system but also improve the efficiency and accuracy of interaction. In the process of visual information processing, the positioning stage and the selection stage are two very important stages. The visual feedback in the positioning stage enables users to timely understand their line-of-sight position, and the visual feedback in the selection stage reminds users to avoid accidentally activating unexpected instructions, thereby improving the reliability and smoothness of interaction. There are respective visual feedbacks for the positioning stage and the selection stage, but different visual feedbacks have different performances.

[0005] However, despite the many advantages of eye control interaction, there are still some problems to be solved in practical applications. Among them, one of the most prominent problems is visual fatigue. Prolonged gazing at the screen by the eyes, frequent eye movement commands, and continuous visual stimulation may cause users to experience visual fatigue, which will not only reduce the work efficiency and experience of users but may even have potential impacts on the health of users.

[0006] The most important thing in eye control interaction is to enable users to clearly identify the position of their line of sight during the interaction process and understand the status and progress of their interaction, that is, to accurately achieve the positioning and selection of the interaction. Therefore, considering the impact of visual fatigue on visual feedback and evaluating the visual feedback of eye control interaction have become urgent problems to be solved. Summary of the Invention

[0007] The purpose of the present invention is to provide an eye control interaction visual feedback evaluation method considering visual fatigue. An eye control interaction visual feedback evaluation method is constructed for the crucial positioning stage and selection stage in the eye control interaction process. Considering the visual fatigue problem brought by eye control interaction, based on the collected user eye movement data, the occurrence time of visual fatigue, and combined with the user evaluation and the user's own load after the experiment, the visual feedback of eye control interaction is evaluated. According to the evaluation results, the visual feedback with better performance in the corresponding stage is selected to reduce visual fatigue and improve the accuracy of eye control interaction.

[0008] The purpose of the present invention is achieved through the following technical solutions:

[0009] An eye control interaction visual feedback evaluation method considering visual fatigue disclosed by the present invention includes the following steps:

[0010] Step 1: Visual feedback is a meaningful prompt for users to understand the current state of the eye control interaction system and infer whether the eye control interaction system responds to the user's operation as expected. Eye control interaction is a continuous interaction process, and different visual feedback should be presented in each interaction stage to inform the user of the current interaction process, so that the user can smoothly proceed to the next step and avoid repeated actions. Eye control interaction is divided into three consecutive stages: positioning, selection, and release. In the process of visual information processing, the processes of positioning and selection represent that the user selects a certain interface element. Therefore, it is necessary to evaluate the visual feedback in the positioning stage and the selection stage, and select a certain interface element according to the visual feedback evaluation results. Positioning refers to pointing to a certain element, selection refers to triggering an action associated with the selected element, and release refers to exiting from the action associated with the selected element.

[0011] The visual feedback in the positioning stage is a visual target, and the visual target is a virtual representation of the user's eye movement. In the positioning stage, information is conveyed through the movement of the visual target, providing users with intuitive visual guidance so that they can accurately understand their fixation point. In the positioning stage, the cross target and circular target in eye control interaction are evaluated, and the evaluation results are used as the visual feedback evaluation results in the positioning stage. A certain interface element is selected according to the visual feedback evaluation results.

[0012] In the selection stage, by changing the appearance of the target area that the user is gazing at to emphasize the user's selection, it further assists the user in confirming the user's interaction intention. The selection stage evaluates the delayed selection mechanism and the sub-selection reconfirmation mechanism in eye control interaction to further assist the user in confirming the user's interaction intention, takes this evaluation result as the visual feedback evaluation result of the selection stage, and selects a certain interface element according to the visual feedback evaluation result.

[0013] The ways to change the appearance of the target area that the user is gazing at include color change, shape adjustment, or animation effects.

[0014] Step 2: Play the positioning and selection tasks using a mobile device. Use the crosshair and circular mark to complete the positioning task, and use the delayed selection mechanism and the sub-selection reconfirmation mechanism to complete the selection task. When the user experiences visual fatigue, the user actively terminates the task, records the occurrence time of the user's visual fatigue, and evaluates different visual feedbacks of the selection stage by having the user fill out a preference questionnaire, evaluates the self-load by filling out the NASA-TLX questionnaire, and uses the eye control interaction device to interact and collect eye movement data.

[0015] The positioning task designed according to the eye control interaction positioning stage is as follows: A "+" symbol appears in the center of the screen to correct the line of sight, and then the user aims at the center point of the randomly appearing yellow border on the screen. After a predetermined time threshold, the yellow border disappears, and this process is repeated until the user experiences visual fatigue. The selection task designed for the selection stage is as follows: A "+" symbol appears in the center of the screen to correct the line of sight, then the target letter will be presented in the center of the screen for the user to memorize, and then letter options will be presented on the screen. Search for the target letter among the letter options. This process lasts for a predetermined time threshold. If the selection is not completed within the specified time, it will directly jump to the next interface, and this process is repeated until the user experiences visual fatigue.

[0016] Step 3: Process the user's eye movement data collected by the eye control interaction device in Step 2, and calculate the positioning error of the visual feedback in the positioning stage and the selection accuracy of the visual feedback in the selection stage. The positioning error refers to the average distance between the user's fixation point and the target center within a predetermined time after the user's fixation point enters the target position. The selection accuracy rate refers to the proportion of correct selections in the selection task relative to the total number of selections required.

[0017] Evaluate the circular mark and the crosshair. First, evaluate according to the occurrence time of visual fatigue, considering the impact of visual fatigue on eye control interaction; then evaluate according to the positioning error to ensure positioning accuracy; then evaluate the load brought to the user by the two visual feedbacks according to the scores of the NASA-TLX questionnaire, and finally evaluate the user's preference for the circular mark and the crosshair according to the scores of the preference questionnaire, complete the evaluation of the visual feedback in the positioning stage, and obtain the evaluation result of the visual feedback in the positioning stage.

[0018] Evaluate the delay selection mechanism and the sub-selection reconfirmation mechanism. First, evaluate according to the onset time of visual fatigue, considering the impact of visual fatigue on eye control interaction; then evaluate according to the selection accuracy rate to ensure the selection accuracy; then evaluate the load brought by the two visual feedbacks to the user according to the NASA-TLX questionnaire score, and evaluate the user's preference for the delay selection mechanism and the sub-selection reconfirmation mechanism according to the preference questionnaire score, complete the evaluation of the visual feedback in the selection stage, and obtain the evaluation result of the visual feedback in the selection stage.

[0019] Step 4: Through the evaluation of the visual feedback in the positioning stage and the selection stage in Step 2 and Step 3, select the visual feedback with better performance according to the evaluation results to complete the positioning task and the selection task. Using the visual feedback selected by this method for eye control interaction can not only ensure a better user experience, reduce the adverse effects brought by visual fatigue to the user, but also reduce the learning cost of operation and ensure the preset operation efficiency. The visual feedback evaluation results include the evaluation results of the visual feedback in the positioning stage and the evaluation results of the visual feedback in the selection stage.

[0020] Beneficial effects:

[0021] 1. A method for evaluating visual feedback of eye control interaction considering visual fatigue disclosed by the present invention constructs a method for evaluating visual feedback of eye control interaction for the positioning stage and the selection stage, which are very crucial in the process of eye control interaction, considers the visual fatigue problem brought by eye control interaction, and evaluates the visual feedback of eye control interaction according to the collected user eye movement data, the onset time of visual fatigue, and in combination with the user evaluation and the user's own load after the experiment. Select the visual feedback according to the evaluation results. The visual feedback selected by this method reduces visual fatigue and ensures the accuracy rate of eye control interaction.

[0022] 2. A method for evaluating visual feedback of eye control interaction considering visual fatigue disclosed by the present invention selects a cross mark and a circular mark to complete the positioning task according to the characteristics of the positioning stage of eye movement interaction, and designs a positioning task that conforms to eye control interaction; according to the characteristics of the selection stage of eye control interaction, selects a delay selection mechanism and a selection reconfirmation mechanism to complete the selection task, and designs a selection task that conforms to eye control interaction. Select the visual feedback in the positioning stage and the selection stage respectively in a targeted manner, and designing the positioning task and the selection task can further improve the quality and efficiency of eye movement data collection.

[0023] 3. An eye control interaction visual feedback evaluation method considering visual fatigue disclosed by the present invention collects the eye movement data of users using an eye movement device, calculates the positioning error and selection accuracy as evaluation indicators of visual feedback according to the data, evaluates the visual feedback from an objective aspect to ensure the accuracy of interaction; obtains the occurrence time of users' visual fatigue when the users actively terminate the task, uses it as a visual fatigue index to evaluate the visual feedback, combines the preference questionnaire filled in by the users to characterize the degree of preference for the visual feedback, and evaluates the self-load by filling in the NASA-TLX questionnaire, and evaluates the visual feedback from a subjective aspect. The evaluation method is made more accurate and comprehensive through the evaluation from both objective and subjective aspects. Description of the Drawings

[0024] Figure 1 It is a flowchart of an eye control interaction visual feedback evaluation method considering visual fatigue of the present invention.

[0025] Figure 2 It is a visual feedback diagram of the positioning stage of an eye control interaction visual feedback evaluation method considering visual fatigue of the present invention.

[0026] Figure 3 It is a visual feedback diagram of the selection stage of an eye control interaction visual feedback evaluation method considering visual fatigue of the present invention.

[0027] Figure 4 It is a diagram of the target position of the positioning task of an eye control interaction visual feedback evaluation method considering visual fatigue of the present invention.

[0028] Figure 5 It is a flowchart of the positioning task of an eye control interaction visual feedback evaluation method considering visual fatigue of the present invention.

[0029] Figure 6 It is a flowchart of the selection task of an eye control interaction visual feedback evaluation method considering visual fatigue of the present invention.

[0030] Figure 7 It is a layout diagram of the letter objects of the selection task of an eye control interaction visual feedback evaluation method considering visual fatigue of the present invention. Detailed Embodiments

[0031] To better illustrate the purpose and advantages of the present invention, the following provides a more detailed description of the invention content.

[0032] Example 1:

[0033] As Figure 1 shown, a method for evaluating eye control interaction visual feedback considering visual fatigue disclosed in this embodiment specifically includes the following implementation steps:

[0034] Step 1: Visual feedback is a meaningful cue used to let users understand the current state of the eye control interaction system and infer whether the eye control interaction system responds to users' operations as expected. Eye control interaction is a continuous interaction process, and different visual feedback should be presented at each interaction stage to inform users of the current interaction process, so that users can proceed smoothly to the next step and avoid repetitive actions. Eye control interaction is divided into three consecutive stages: positioning, selection, and release. During the visual information processing, the processes of positioning and selection represent that the user selects a certain interface element. Therefore, it is necessary to evaluate the visual feedback in the positioning stage and the selection stage, and select a certain interface element according to the evaluation result of the visual feedback. Positioning means pointing to an element, selection means triggering an action associated with the selected element, and release means exiting from the action associated with the selected element.

[0035] The visual feedback in the positioning stage is a cursor, which is a virtual representation of the user's eye movement. In the positioning stage, information is conveyed through the movement of the cursor, providing users with intuitive visual guidance so that they can accurately understand their fixation point. In the positioning stage, the crosshair and circular mark in the eye control interaction are evaluated, and the evaluation result is used as the evaluation result of the visual feedback in the positioning stage. A certain interface element is selected according to the evaluation result of the visual feedback.

[0036] In the selection stage, the appearance of the target area where the user is fixating is changed to emphasize the user's selection and further assist the user in confirming their interaction intention. In the selection stage, the delayed selection mechanism and the sub-selection reconfirmation mechanism in the eye control interaction are evaluated to further assist the user in confirming their interaction intention. The evaluation result is used as the evaluation result of the visual feedback in the selection stage. A certain interface element is selected according to the evaluation result of the visual feedback.

[0037] The ways to change the appearance of the target area where the user is fixating include color change, shape adjustment, or animation effect.

[0038] Step 2: Use a mobile device to play the positioning and selection tasks. Use the crosshair and circular mark to complete the positioning task, both with a size of 32px, as Figure 2 shown; use the delayed selection mechanism and the sub-selection reconfirmation mechanism to complete the selection task. The dwell time of the delayed selection mechanism is set to 1000ms. During the selection process, the semi-transparent white gradually fills the entire target, and after 1000ms, the yellow border turns red. The sub-selection reconfirmation mechanism requires the user to fixate on the target for 300ms, and the animation effect is the same as that of the delayed selection mechanism. Then a sub-target (a yellow square with a size of 75px × 75px) appears 20px to the right. Within 500ms, the gaze shifts to the sub-target, fixates on the sub-target for 200ms, and then the sub-target fills with red and the yellow border turns red, indicating selection, as Figure 3As shown, when visual fatigue occurs to the user, the user actively terminates the task, records the occurrence time of visual fatigue, evaluates the visual feedback in different selection stages by having the user fill out a preference questionnaire, evaluates the self-load by filling out the NASA-TLX questionnaire, uses an eye-controlled interaction device for interaction and collects eye movement data.

[0039] The positioning task designed according to the eye-controlled interaction positioning stage is as follows: The experimental target object is a yellow border with a center point, which will randomly appear at any position on the screen, such as Figure 4 shown. The sizes of the yellow border include three types: small (75px), medium (100px), and large (125px), and the size that appears each time is random. At the beginning of the task, a "+" sign appears in the center of the screen for 1000 ms to correct the line of sight, and then the user aims at the center point of the yellow border randomly appearing on the screen with the eyes. After 3000 ms, the yellow border disappears, and this process is repeated until visual fatigue occurs to the user. The positioning task process is as Figure 5 shown. The selection task designed in the selection stage is as follows: The experimental target object is a yellow English letter in Microsoft YaHei size 72 presented in the center of a 150px × 150px yellow border. The 4×5 letter objects are randomly selected from 26 capital English letters without repetition, and their layout on the screen is as Figure 6 shown. The horizontal distance between two adjacent yellow borders is 195px, and the vertical distance is 96px. At the beginning of the task, a "+" sign appears in the center of the screen for 1000 ms to correct the line of sight, and then the target letter will be presented in the center of the screen for 1000 ms for the user to memorize. Then the letter options will be presented on the screen, and the user looks for the target letter among the letter options. This process lasts for 3000 ms. If the selection is not completed within the specified time, it will directly jump to the next interface, and this process is repeated until visual fatigue occurs to the user. The task process is as Figure 7 shown.

[0040] Step 3: Process the user eye movement data collected by using the eye-controlled interaction device in Step 2, and calculate the positioning error of the visual feedback in the positioning stage and the selection accuracy rate of the visual feedback in the selection stage. The positioning error refers to the average distance between the user's fixation point and the target center within a predetermined time after the user's fixation point enters the target position. The selection correct rate refers to the proportion of correct selections in the selection task relative to the total number of selections required.

[0041] Evaluate the circular mark and the cross mark. First, evaluate according to the occurrence time of visual fatigue, considering the influence of visual fatigue on eye-controlled interaction; then evaluate according to the positioning error to ensure positioning accuracy; then evaluate the load brought by the two visual feedbacks to the user according to the NASA-TLX questionnaire score, and finally evaluate the user's preference for the circular mark and the cross mark according to the preference questionnaire score, complete the evaluation of the visual feedback in the positioning stage, and obtain the evaluation result of the visual feedback in the positioning stage.

[0042] Evaluate the delay selection mechanism and the sub-selection reconfirmation mechanism. First, evaluate according to the onset time of visual fatigue, considering the impact of visual fatigue on eye control interaction; then evaluate according to the selection accuracy rate to ensure the selection accuracy; then evaluate the load brought by the two visual feedbacks to the user according to the NASA-TLX questionnaire score, and finally evaluate the user's preference for the delay selection mechanism and the sub-selection reconfirmation mechanism according to the preference questionnaire score, complete the evaluation of the visual feedback in the selection stage, and obtain the evaluation result of the visual feedback in the selection stage.

[0043] Step 4: Evaluate the visual feedback in the positioning stage and the selection stage through Step 2 and Step 3, and select the better-performing visual feedback according to the evaluation results to complete the positioning task and the selection task. Using the visual feedback selected by this method for eye control interaction can not only ensure a better user experience, reduce the adverse effects brought by visual fatigue to the user, but also reduce the learning cost of operation and ensure the preset operation efficiency. The visual feedback evaluation results include the evaluation results of the visual feedback in the positioning stage and the evaluation results of the visual feedback in the selection stage.

[0044] The above specific description further details the purpose, technical solution and beneficial effects of the invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for evaluating eye-controlled interactive visual feedback considering visual fatigue, characterized in that: The following steps are included: Step 1: Visual feedback is a meaningful prompt that allows users to understand the current state of the eye-controlled interaction system and infer whether the eye-controlled interaction system responds to the user's operation as expected; eye-controlled interaction is a continuous interaction process, and different visual feedback should be presented at each interaction stage to inform the user of the current interaction process so that the user can proceed to the next step smoothly and avoid repeated actions; eye-controlled interaction is divided into three continuous stages: positioning, selection, and release. In the process of visual information processing, the positioning and selection processes represent the user's selection of a certain interface element. It is necessary to evaluate the visual feedback of the positioning stage and the selection stage, and select a certain interface element according to the visual feedback evaluation results; positioning refers to pointing to an element, selection refers to triggering the action associated with the selected element, and release refers to exiting from the action associated with the selected element; The visual feedback in the positioning stage is the sight mark, which is a virtual representation of the user's eye movement. In the positioning stage, information is conveyed through the movement of the sight mark, providing users with intuitive visual guidance so that users can accurately understand their focus. In the positioning stage, the cross mark and the circular mark in the eye control interaction are evaluated, and the evaluation result is used as the visual feedback evaluation result of the positioning stage. A certain interface element is selected according to the visual feedback evaluation result. In the selection phase, the appearance of the target area where the user is looking is changed to emphasize the user's choice and further assist the user in confirming the user's interaction intention; In the selection stage, the delayed selection mechanism and sub-selection reconfirmation mechanism in the eye-controlled interaction are evaluated to further assist the user in confirming the user's interaction intention. The evaluation result is used as the visual feedback evaluation result of the selection stage, and a certain interface element is selected according to the visual feedback evaluation result; Changing the appearance of the target area the user is looking at may include changing color, adjusting shape, or animation. Step 2: Use a mobile device to play the positioning and selection tasks, use the cross mark and the circular mark to complete the positioning task, use the delayed selection mechanism and the sub-selection reconfirmation mechanism to complete the selection task, the user actively terminates the task when visual fatigue occurs, and the time when the user's visual fatigue occurs is recorded. The user is asked to fill out a preference questionnaire to evaluate the visual feedback at different selection stages, fill out the NASA-TLX questionnaire to evaluate their own workload, and use an eye-controlled interactive device to interact and collect eye movement data; Step 3: Process the user eye movement data collected by the eye-control interaction device in step 2, and calculate the positioning error of the visual feedback in the positioning stage and the selection accuracy of the visual feedback in the selection stage; the positioning error refers to the average distance between the user's gaze point and the target center within a predetermined time after the user's gaze point enters the target position; the selection accuracy refers to the proportion of correct choices in the selection task relative to the total number of required choices; To evaluate the circular mark and the cross mark, first evaluate them based on the time when visual fatigue occurs, considering the impact of visual fatigue on eye control interaction; then evaluate them based on the positioning error to ensure positioning accuracy; then evaluate the load brought to users by the two visual feedbacks based on the NASA-TLX questionnaire scores, and evaluate users' preferences for the circular mark and the cross mark based on the preference questionnaire scores, completing the evaluation of the visual feedback in the positioning stage and obtaining the evaluation results of the visual feedback in the positioning stage; To evaluate the delayed selection mechanism and the sub-selection reconfirmation mechanism, firstly, the time of visual fatigue occurrence is evaluated to consider the impact of visual fatigue on eye control interaction; then, the selection accuracy is evaluated to ensure the accuracy of selection; then, the load of the two visual feedbacks on users is evaluated based on the NASA-TLX questionnaire scores; finally, the user's preference for the delayed selection mechanism and the sub-selection reconfirmation mechanism is evaluated based on the preference questionnaire scores, completing the evaluation of the visual feedback in the selection stage and obtaining the evaluation results of the visual feedback in the selection stage; Step 4: Evaluate the visual feedback in the positioning stage and the selection stage through steps 2 and 3, and select the visual feedback with better performance to complete the positioning task and the selection task according to the evaluation results; selecting the best visual feedback for eye control interaction according to this method can not only ensure a better user experience and reduce the disadvantages of visual fatigue to users, but also reduce the learning cost of the operation and ensure the preset operation efficiency; the visual feedback evaluation results include the evaluation results of the visual feedback in the positioning stage and the evaluation results of the visual feedback in the selection stage.

2. The eye-controlled interactive visual feedback evaluation method considering visual fatigue as claimed in claim 1, characterized in that: In step one, The visual feedback in the positioning stage is the sight mark, which is a virtual representation of the user's eye movement. In the positioning stage, information is conveyed through the movement of the sight mark, providing users with intuitive visual guidance so that users can accurately understand their focus. In the positioning stage, the cross mark and the circular mark in the eye control interaction are evaluated, and the evaluation result is used as the visual feedback evaluation result of the positioning stage. A certain interface element is selected according to the visual feedback evaluation result. In the selection phase, the appearance of the target area where the user is looking is changed to emphasize the user's choice and further assist the user in confirming the user's interaction intention; In the selection stage, the delayed selection mechanism and sub-selection reconfirmation mechanism in the eye-controlled interaction are evaluated to further assist the user in confirming the user's interaction intention. The evaluation result is used as the visual feedback evaluation result of the selection stage, and a certain interface element is selected according to the visual feedback evaluation result.

3. The eye-controlled interactive visual feedback evaluation method considering visual fatigue as claimed in claim 2, characterized in that: In step 1, the manner of changing the appearance of the target area where the user is looking includes color change, shape adjustment or animation effect.

4. The eye-controlled interactive visual feedback evaluation method considering visual fatigue as claimed in claim 1 or 2, characterized in that: In step 2, the positioning task designed according to the eye movement interaction positioning stage is: a "+" sign appears in the center of the screen to correct the line of sight, and then the eyes are aimed at the center point of the yellow border that appears randomly on the screen. After a predetermined time threshold, the yellow border disappears, and this process is repeated until the user experiences visual fatigue; The selection task designed in the selection stage is: a "+" sign appears in the center of the screen to correct the line of sight, and then the target letter is presented in the center of the screen for the user to remember. Then letter options are presented on the screen, and the target letter is found among the letter options. This process lasts for a predetermined time threshold. If the selection is not completed within the specified time, it will jump directly to the next interface. This process is repeated until the user experiences visual fatigue.

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