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

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.

Study Overview

• Status: Completed
• Conditions: Myopia; Visual Fatigue
• Intervention / Treatment: Behavioral: Dynamic Defocus Mode

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 Type: Interventional
• Enrollment (Actual): 36
• Phase: Not Applicable

Contacts and Locations

Study Locations

• China
  • Beijing Municipality
    • Beijing, Beijing Municipality, China, 100730
      • Beijing Tongren Hospitol,Capital Medical University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

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.

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.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

5

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Control group; 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.
Experimental: Intervention Group A (Low defocus amplitude and high frequency); 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 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.
Experimental: Intervention Group B (low defocus amplitude and low frequency); 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 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.
Experimental: Intervention Group C (high defocus amplitude and high frequency); 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 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.
Experimental: Intervention Group D (high defocus amplitude and low frequency); 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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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 Outcome Measures

Outcome Measure	Measure Description	Time Frame
Critical Flicker Fusion Frequency(CFF)	To evaluate the degree of eye fatigue, with lower measured values indicating a higher degree of fatigue.	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.	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.	Baseline (before intervention), immediately after the 50-minute video-watching task for each of the five sessions, totaling ten completions per participant.

Other Outcome Measures

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

Collaborators and Investigators

• Sponsor: Beijing Tongren Hospital

Study record dates

Study Major Dates

• Study Start (Actual): August 20, 2025
• Primary Completion (Actual): November 20, 2025
• Study Completion (Actual): November 30, 2025

Study Registration Dates

• First Submitted: September 20, 2025
• First Submitted That Met QC Criteria: December 5, 2025
• First Posted (Actual): December 18, 2025

Study Record Updates

• Last Update Posted (Actual): December 18, 2025
• Last Update Submitted That Met QC Criteria: December 5, 2025
• Last Verified: May 1, 2025

More Information

Terms related to this study

• Keywords: visual function; Visual Fatigue; Dynamic Defocus Display Technology; Repeated Measures Design; Longitudinal Chromatic Aberration
• Additional Relevant MeSH Terms: Eye Diseases; Refractive Errors; Myopia; Asthenopia
• Other Study ID Numbers: TREC2025-KY160

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No