Visual FatigueNCT07291856
Exploring the Impact of Dynamic Defocus Display Schemes on Ocular Health Indicators
A study testing Dynamic Defocus Mode in people with Visual Fatigue and Myopia, run by Beijing Tongren Hospital at 1 site in China.
Trial summary
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… Read more about this study
- Who is it for?
- Ages 20 to 40 yearsHealthy volunteers can take part
- Conditions the study is for
- Visual Fatigue, Myopia
- What is being tested?
- Dynamic Defocus Mode
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 36 participants
- Where
- 1 siteChina
- Study dates
- 20 Aug 2025to 30 Nov 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 20 to 40 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- 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 informed consent form.
Who cannot join
- 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.
Trial locations and contacts
1 site in 1 country.
China1 site
Beijing Tongren Hospitol,Capital Medical University
Beijing, Beijing Municipality, 100730
About this study
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.
Read the detailed description
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.
- Conditions
- Visual Fatigue, Myopia
- Being tested
- Dynamic Defocus Mode
- Keywords
- Dynamic Defocus Display Technology, Visual Fatigue, visual function, Repeated Measures Design, Longitudinal Chromatic Aberration
- Medical subject headings
- Asthenopia, Myopia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Dynamic Defocus ModeBehavioural
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.
| Study group | Role | What they receive |
|---|---|---|
| Control group | No intervention | 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. |
| Intervention Group A (Low defocus amplitude and high frequency) | Experimental | 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. Receives: Behavioral: Dynamic Defocus Mode |
| Intervention Group B (low defocus amplitude and low frequency) | Experimental | 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. Receives: Behavioral: Dynamic Defocus Mode |
| Intervention Group C (high defocus amplitude and high frequency) | Experimental | 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. Receives: Behavioral: Dynamic Defocus Mode |
| Intervention Group D (high defocus amplitude and low frequency) | Experimental | 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. Receives: Behavioral: Dynamic Defocus Mode |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: 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.
Measured: Baseline (before intervention), immediately after the 50-minute video-watching task for each of the five sessions, totaling ten completions per participant.
Secondary outcomes (3)
Critical Flicker Fusion Frequency(CFF)
To evaluate the degree of eye fatigue, with lower measured values indicating a higher degree of fatigue.
Measured: 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.
Measured: 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.
Measured: Baseline (before intervention), immediately after the 50-minute video-watching task for each of the five sessions, totaling ten completions per participant.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Dec 2025
- Study start20 Aug 2025
- Primary completion20 Nov 2025
- Study completion30 Nov 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Visual FatigueStudies of the same condition, open and under way.
- More trials run by Beijing Tongren HospitalThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- This study is designed with a total of five groups, where participants will sequentially and randomly undergo all the intervention procedures.
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 36 participants (actual)
Sponsor and investigators
- Lead sponsor
- Beijing Tongren Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07291856
- Sponsor's protocol ID
- TREC2025-KY160
- Status last verified
- May 2025
- First submitted
- 20 Sep 2025
- Last updated
- 18 Dec 2025
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 18 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Exploring the Impact of Dynamic Defocus Display Schemes on Ocular Health Indicators
- ClinicalTrials.gov ID
- NCT07291856
- Acronym / sponsor ID
- TREC2025-KY160
- Conditions
- Visual Fatigue, Myopia
- Keywords
- Dynamic Defocus Display Technology, Visual Fatigue, visual function, Repeated Measures Design, Longitudinal Chromatic Aberration
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 36 participants (actual)
- Lead sponsor
- Beijing Tongren HospitalUniversity, hospital or other
- Study start
- 20 Aug 2025 (actual)
- Primary completion
- 20 Nov 2025 (actual)
- Study completion
- 30 Nov 2025 (actual)
- First posted
- 18 Dec 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
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.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, investigator)
- Number of arms
- 5
- Model description
- This study is designed with a total of five groups, where participants will sequentially and randomly undergo all the intervention procedures.
| Arm | Type | Receives |
|---|---|---|
| Control group | No intervention | –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. |
| Intervention Group A (Low defocus amplitude and high frequency) | Experimental | Behavioral: Dynamic Defocus ModeParticipants 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. |
| Intervention Group B (low defocus amplitude and low frequency) | Experimental | Behavioral: Dynamic Defocus ModeParticipants 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. |
| Intervention Group C (high defocus amplitude and high frequency) | Experimental | Behavioral: Dynamic Defocus ModeParticipants 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. |
| Intervention Group D (high defocus amplitude and low frequency) | Experimental | Behavioral: Dynamic Defocus ModeParticipants 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. |
Who may qualify
- Ages
- 20 to 40 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (6 listed)
- 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;
Key exclusion criteria (5 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Dynamic Defocus ModeParticipants 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. | Behavioural | Intervention Group A (Low defocus amplitude and high frequency), Intervention Group B (low defocus amplitude and low frequency), Intervention Group C (high defocus amplitude and high frequency), Intervention Group D (high defocus amplitude and low frequency) |
Primary outcome
Binocular Visual Function(amplitude of accommodation)
Time frame: Baseline (before intervention), immediately after the 50-minute video-watching task for each of the five sessions, totaling ten completions per participant.
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.
Binocular Visual Function（accommodative facility）
Time frame: Baseline (before intervention), immediately after the 50-minute video-watching task for each of the five sessions, totaling ten completions per participant.
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.
3 secondary outcomes
Critical Flicker Fusion Frequency(CFF)
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
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
Time frame: Baseline (before intervention), immediately after the 50-minute video-watching task for each of the five sessions, totaling ten completions per participant.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 18 Dec 2025.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Dynamic Defocus Mode in people with Visual Fatigue and Myopia, run by Beijing Tongren Hospital at 1 site in China.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 18 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Binocular Visual Function(amplitude of accommodation) (time frame: Baseline (before intervention), immediately after the 50-minute video-watching task for each of the five sessions, totaling ten completions per participant.). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 18 Dec 2025.