Exploring the Impact of Dynamic Defocus Display Schemes on Ocular Health Indicators

NCT07291856 | Completed

• 1 other identifier: TREC2025-KY160
• Study Type: interventional
• Target: 36
• Locations: 1 country
• Sites: 1

Brief 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 application and widespread adoption.

Conditions

Visual Fatigue; Myopia

Keywords

Dynamic Defocus Display Technology; Visual Fatigue; visual function; Repeated Measures Design; Longitudinal Chromatic Aberration

Outcome Measures

Primary Outcomes (2)

• 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.

  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.

  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)

  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

  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

  Baseline (before intervention), immediately after the 50-minute video-watching task for each of the five sessions, totaling ten completions per participant.

Other Outcomes (2)

• Optical Coherence Tomography Angiography

  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

  Baseline (before intervention), immediately after the 50-minute video-watching task for each of the five sessions, totaling ten completions per participant.

Study Arms (5)

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.

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.

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.

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.

Behavioral: Dynamic Defocus Mode

Interventions

Dynamic Defocus Mode BEHAVIORAL

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.

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)

Eligibility Criteria

• Age: 20 Years - 40 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• Beijing Tongren Hospital: lead

Study Sites (1)

Beijing Tongren Hospitol,Capital Medical University

Beijing, Beijing Municipality, 100730, China

Location

MeSH Terms

Conditions

Asthenopia; Myopia

Condition Hierarchy (Ancestors)

Eye Diseases; Refractive Errors

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Masking Details: In this clinical trial, the masking is applied to the participants and the study staff who conduct the assessments. The participants are single-blinded, meaning they are unaware of the specific dynamic defocus mode they are assigned to during the trial. This is to ensure that their subjective responses, such as those recorded in the visual fatigue questionnaire, are not influenced by their knowledge of the intervention. The study staff who perform the assessments, including the measurement of critical flicker fusion frequency (CFF), accommodative function, and other ocular health indicators, are also blinded to the group assignments. This helps to prevent any potential bias in the data collection process, ensuring that the measurements are objective and reliable. The randomization sequence and group assignments are managed by a third-party institution, which maintains the integrity of the blinding. Only after all data have been collected and the initial analysis is complete will the bl
• Purpose: PREVENTION
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: This study is designed with a total of five groups, where participants will sequentially and randomly undergo all the intervention procedures.

Study Record Dates

• First Submitted: September 20, 2025
• First Posted: December 18, 2025
• Study Start: August 20, 2025
• Primary Completion: November 20, 2025
• Study Completion: November 30, 2025
• Last Updated: December 18, 2025

Record last verified: 2025-05

Data Sharing

• IPD Sharing: Will not share

Locations

CN (1)