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

Capital Medical University

Status: Completed

Conditions: Myopia; Visual Fatigue

Treatments: Behavioral: Dynamic Defocus Mode

Study type: Interventional

Funder types: Other

Identifiers

NCT07291856

TREC2025-KY160

Details and patient eligibility

About

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.

Full 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.

Enrollment: 36 patients

Sex: All

Ages: 20 to 40 years old

Volunteers: Accepts Healthy Volunteers

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.

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Double Blind

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36 participants in 5 patient groups

Control group

No Intervention group

Description:

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 group

Description:

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.

Treatment:

Behavioral: Dynamic Defocus Mode

Intervention Group B (low defocus amplitude and low frequency)

Experimental group

Description:

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.

Treatment:

Behavioral: Dynamic Defocus Mode

Intervention Group C (high defocus amplitude and high frequency)

Experimental group

Description:

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.

Treatment:

Behavioral: Dynamic Defocus Mode

Intervention Group D (high defocus amplitude and low frequency)

Experimental group

Description:

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.

Treatment:

Behavioral: Dynamic Defocus Mode