An interventional study of Dynamic Defocus Mode in Visual Fatigue and Myopia, sponsored by Beijing Tongren Hospital. Completed at 1 site in China. Open to participants aged 20 Years to 40 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-12-18.
Sponsored by Beijing Tongren Hospital · Not applicable, Interventional, and Prevention
The present study is designed to explore the effects of dynamic defocus display technology on ocular health parameters using rigorous scientific approaches. It further examines the mechanisms through which this technology alleviates visual fatigue, thereby providing robust clinical evidence to support its practical application and widespread adoption.
Research Content Recruit adults who meet the inclusion criteria and have long-term use of VDT (Visual Display Terminal) devices for the trial.
Compare the impact of different dynamic defocus modes on the visual fatigue symptoms of the subjects.
Analyze the mechanisms through which dynamic defocus modes alleviate visual fatigue.
Research Outcome Measures Primary Outcome Measures and Definitions Binocular Visual Function: A series of assessments of visual ability, including accommodative function (amplitude of accommodation, accommodative facility) and vergence function (near point of convergence, AC/A ratio).
Secondary Outcome Measures and Definitions Critical Flicker Fusion Frequency (CFF): To evaluate the degree of eye fatigue, with lower measured values indicating a higher degree of fatigue.
Visual Fatigue Questionnaire Score: To assess the subjective level of visual fatigue experienced by the subjects.
Refraction Results: To monitor changes in refractive status during the trial and evaluate the impact of different dynamic defocus modes on refractive state when using VDT devices at near distance.
67 studies on the registry are indexed under Asthenopia; 10 are open to participants now.
This study's enrollment of 36 is below the median of 56 across 56 interventional studies indexed under Asthenopia.
Browse Asthenopia studies →Beijing Tongren Hospital is the lead sponsor of 164 studies on the registry; 54 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Adults aged between 20 and 40 years, regardless of gender;
Refractive anisometropia ≤2.5D and corrected visual acuity of 1.0 or above in both eyes;
Habitual long-term use of electronic devices with LED light sources, such as computers and smartphones;
Currently not using any other blue light protection products or having ceased the use of such products for at least 2 weeks;
No known visually significant ophthalmic diseases;
Willing to participate in the trial and having signed the form.
Exclusion Criteria:
Abnormal accommodative function or other visual function abnormalities (e.g., strabismus, amblyopia);
Severe dry eye or history of ocular medication use;
Acute or chronic ocular surface inflammation, keratoconus, history of ocular surgery (e.g., refractive surgery), systemic diseases, or other conditions (e.g., wearing orthokeratology lenses and using atropine);
Photosensitivity, history of epilepsy, etc.;
Individuals unable to cooperate with the examination.
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
This group serves as the baseline comparison. Participants will perform the video-watching task on a conventional display with no intervention, allowing for the assessment of typical visual fatigue and ocular health indicators under standard conditions.
Participants will use a display with Dynamic Defocus Mode with low defocus amplitude and high frequency to perform a video browsing task. This group is designed with a specific dynamic defocus adjustment scheme, aimed at investigating the extent to which different dynamic defocus schemes can improve visual fatigue. Participants will be single-blinded to their group assignment. The intervention involves Dynamic Defocus Mode 1 and follows the VDT task protocol as designed in the trial.
Behavioral: Dynamic Defocus Mode
Participants will use a display with Dynamic Defocus Mode with low defocus amplitude and low frequency to perform a video browsing task. This group is designed with a specific dynamic defocus adjustment scheme, aimed at investigating the extent to which different dynamic defocus schemes can improve visual fatigue. Participants will be single-blinded to their group assignment. The intervention involves Dynamic Defocus Mode 1 and follows the VDT task protocol as designed in the trial.
Behavioral: Dynamic Defocus Mode
Participants will use a display with Dynamic Defocus Mode with high defocus amplitude and high frequency to perform a video browsing task. This group is designed with a specific dynamic defocus adjustment scheme, aimed at investigating the extent to which different dynamic defocus schemes can improve visual fatigue. Participants will be single-blinded to their group assignment. The intervention involves Dynamic Defocus Mode 1 and follows the VDT task protocol as designed in the trial.
Behavioral: Dynamic Defocus Mode
Participants will use a display with Dynamic Defocus Mode with high defocus amplitude and low frequency to perform a video browsing task. This group is designed with a specific dynamic defocus adjustment scheme, aimed at investigating the extent to which different dynamic defocus schemes can improve visual fatigue. Participants will be single-blinded to their group assignment. The intervention involves Dynamic Defocus Mode 1 and follows the VDT task protocol as designed in the trial.
Behavioral: Dynamic Defocus Mode
Participants are required to complete a 50-minute video-watching task using a terminal display device that contains video content processed with different dynamic defocus modes. Specifically, participants will watch the same series of videos in different dynamic defocus modes. Participants will complete a total of 5 sets of video tasks (including the control group) in a random order.
Binocular Visual Function(amplitude of accommodation)
The amplitude of accommodation refers to the maximum amount of accommodative power that the eye can exert to focus on near objects, typically measured in diopters.
Time frame: Baseline (before intervention), immediately after the 50-minute video-watching task for each of the five sessions, totaling ten completions per participant.
Binocular Visual Function（accommodative facility）
Accommodative facility, measured using a 2D flipper in cycles per minute (cpm), reflects the eye's ability to rapidly and efficiently change focus between near and far objects, indicating the dynamic functioning of the accommodative system.
Time frame: Baseline (before intervention), immediately after the 50-minute video-watching task for each of the five sessions, totaling ten completions per participant.
Critical Flicker Fusion Frequency(CFF)
To evaluate the degree of eye fatigue, with lower measured values indicating a higher degree of fatigue.
Time frame: Baseline (before intervention), immediately after the 50-minute video-watching task for each of the five sessions, totaling ten completions per participant.
Visual Fatigue Questionnaire Score
The Computer Vision Syndrome Questionnaire (CVS-Q), which has been independently modified, comprises 16 response items. Participants will complete the questionnaire before and after the task to assess changes in ocular strain symptoms. By comparing the questionnaire scores obtained when using different dynamic defocus modes of the VDT devices, the effectiveness of dynamic defocus modes in alleviating subjective symptoms of ocular strain will be evaluated.
Time frame: Baseline (before intervention), immediately after the 50-minute video-watching task for each of the five sessions, totaling ten completions per participant.
Refractive error status
The refractive error status of the subjects was determined using a combination of automatic refractometer and subjective refraction, with results expressed in diopters.
Time frame: Baseline (before intervention), immediately after the 50-minute video-watching task for each of the five sessions, totaling ten completions per participant.
Optical Coherence Tomography Angiography
Optical Coherence Tomography Angiography (OCTA) is a non-invasive imaging technique that provides detailed cross-sectional images of retinal and choroidal structures. It is particularly useful for evaluating the choroidal thickness, which can be measured precisely in micrometers.
Time frame: Baseline (before intervention), immediately after the 50-minute video-watching task for each of the five sessions, totaling ten completions per participant.
Multispectral refraction topography
Multispectral Refraction Topography (MRT) is an advanced imaging technique used to map the refractive properties of the eye across multiple wavelengths. By analyzing the eye's refractive profile at different spectral ranges, MRT offers a comprehensive understanding of the eye's optical characteristics.
Time frame: Baseline (before intervention), immediately after the 50-minute video-watching task for each of the five sessions, totaling ten completions per participant.
Plan to share: No
No publications or documents are linked to this record.
Ran from Aug 2025 to primary completion in Nov 2025, 3 months.
Of 31 non-industry interventional studies with no phase under Asthenopia, half reached primary completion within 3 months of starting (the median), counting those still running; a quarter within 2 and three quarters within 9. This study's 3 months is close to that.
Counting every sponsor, half of 38 studies reached it within 3 months; a quarter within 2 and three quarters within 9.
How these figures are worked out, and which studies are left out of them.
This study is completed, as verified in May 2025. You cannot join it, but the record below documents what was studied.
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