An interventional study of Full-spectrum screen bar light and Brightness-matched screen task without screen bar lighting in Visual Fatigue, Dry Eye and Computer Vision Syndrome, sponsored by Zhongshan Ophthalmic Center, Sun Yat-sen University. Not yet recruiting at 1 site in China. Open to participants aged 18 Years to 35 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-18.
Sponsored by Zhongshan Ophthalmic Center, Sun Yat-sen University · Not applicable, Interventional, and Prevention
This study will evaluate whether full-spectrum screen bar lighting can reduce eye fatigue and dry eye symptoms after a standardized screen task. Prolonged screen use is common in daily work and study and may cause blurred vision, eye soreness, dryness, headache, and reduced attention. Light environment may be one way to improve visual comfort during screen use, but more controlled clinical evidence is needed.
In this randomized, parallel-group controlled study, 112 healthy adult participants will be assigned to either a full-spectrum screen bar lighting group or a brightness-matched control group without screen bar lighting. Participants in both groups will complete an approximately 2-hour standardized screen task in a controlled laboratory environment. The study will compare changes before and after the task in objective and subjective measures of visual fatigue and dry eye, including critical flicker fusion frequency, visual fatigue questionnaire scores, eye movement and blinking parameters, pupil parameters, tear film-related measurements, and dry eye symptom scores. Safety and discomfort during the study will also be recorded.
Prolonged use of electronic screens is increasingly common in work, study, and daily life and may lead to visual fatigue and dry eye-related symptoms. These symptoms may include blurred vision, eye soreness, dryness, headache, and reduced attention. Although behavioral strategies such as taking breaks and adjusting viewing distance are commonly recommended, their effectiveness may be limited by individual adherence. Optimizing the lighting environment during screen use may provide a standardized and practical approach to improving visual comfort.
This is a single-center, randomized, parallel-group controlled study designed to evaluate the effects of full-spectrum screen bar lighting during a standardized screen task. Eligible healthy adult participants with regular daily screen exposure will be randomly assigned in a 1:1 ratio to either a full-spectrum screen bar lighting group or a brightness-matched control group without screen bar lighting. Both groups will complete the same approximately 2-hour standardized screen task in a controlled laboratory environment. The task may include computer-based text processing, screen reading, or viewing specified video materials, with the task content, duration, and completion requirements kept consistent between groups.
Assessments will be performed before and immediately after the standardized screen task. The study will evaluate changes in objective and subjective measures of visual fatigue, ocular behavioral parameters, and dry eye-related indicators. These include critical flicker fusion frequency, visual fatigue questionnaire scores, eye movement, blinking and pupil parameters, tear film-related measurements, conjunctival redness, and dry eye symptom scores. Safety will be assessed by recording any discomfort or adverse events, such as glare discomfort, eye dryness, tearing, conjunctival redness, headache, nausea, or dizziness.
This study is expected to provide clinical evidence on whether full-spectrum screen bar lighting can help reduce screen-related visual fatigue and dry eye symptoms, and may support the development of lighting strategies for visual health in daily screen-use environments.
67 studies on the registry are indexed under Asthenopia; 10 are open to participants now.
This study's planned enrollment of 112 is above the median of 56 across 56 interventional studies indexed under Asthenopia.
Browse Asthenopia studies →Zhongshan Ophthalmic Center, Sun Yat-sen University is the lead sponsor of 164 studies on the registry; 80 are open to participants now.
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Exclusion Criteria:
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.
Participants assigned to this arm will complete an approximately 2-hour standardized screen task in a controlled laboratory environment using a full-spectrum screen bar light (MB23001032H-1B) as task lighting. The screen task may include computer-based text processing, screen reading, or viewing specified video materials. Task content, duration, and completion requirements will be kept consistent with the control arm.
Device: Full-spectrum screen bar light
Participants assigned to this arm will complete the same approximately 2-hour standardized screen task in the same controlled laboratory environment without using a full-spectrum screen bar light or any additional screen bar lighting. Screen brightness will be adjusted to match the brightness condition of the full-spectrum screen bar lighting arm. Task content, duration, and completion requirements will be kept consistent with the experimental arm.
Other: Brightness-matched screen task without screen bar lighting
The full-spectrum screen bar light will be used as task lighting during an approximately 2-hour standardized screen task in a controlled laboratory environment. Participants will complete computer-based text processing, screen reading, or viewing of specified video materials to simulate prolonged near-screen use.
Participants will complete the standardized screen task without using a screen bar light. Screen brightness will be adjusted to match the brightness condition of the full-spectrum screen bar lighting arm. The task type, content, duration, and completion requirements will be the same as those in the experimental arm.
Change in Critical Flicker Fusion Frequency
Critical flicker fusion frequency (CFF) will be measured in Hz using the Handy Flicker HF-III device. The outcome will be calculated as the post-task CFF value minus the baseline CFF value. This measure will be used as an objective indicator of visual fatigue after the standardized screen task.
Time frame: Baseline and immediately after completion of the approximately 2-hour standardized screen task
Change in Computer Vision Syndrome Questionnaire Score
The Computer Vision Syndrome Questionnaire (CVS-Q) will be used to assess subjective visual fatigue symptoms. The outcome will be calculated as the post-task total score minus the baseline total score.
Time frame: Baseline and immediately after completion of the approximately 2-hour standardized screen task
Change in EyeFatigue Tracker Ocular Behavioral Parameters
Ocular behavioral parameters will be recorded using the EyeFatigue Tracker system during a standardized 1-minute reading task. The assessment will include eye movement, blink, and pupil-related parameters. Change values will be calculated as post-task values minus baseline values.
Time frame: Baseline and immediately after completion of the approximately 2-hour standardized screen task
Change in Keratograph 5M Ocular Surface Assessment
Objective ocular surface and dry eye-related parameters will be measured using the Keratograph 5M system. The assessment will include non-invasive tear breakup time, tear meniscus height, and conjunctival redness. Change values will be calculated as post-task values minus baseline values.
Time frame: Baseline and immediately after completion of the approximately 2-hour standardized screen task
Change in Eye Dryness Score on the 0-100 Visual Analog Scale
Eye dryness will be assessed using the Eye Dryness Score on a 0-100 visual analog scale. Participants will indicate the severity of eye dryness by placing a mark on a 100-mm horizontal line, where 0 represents no eye dryness and 100 represents the most severe eye dryness. Higher scores indicate worse symptoms. The change score will be calculated as the score immediately after the standardized screen task minus the baseline score. A positive change indicates worsening of eye dryness, whereas a negative change indicates improvement.
Time frame: Baseline and immediately after completion of the approximately 2-hour standardized screen task
Plan to share: No
Start is estimated for Sep 2026; primary completion for Apr 2027, 6 months later.
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 planned 6 months is above 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 not yet recruiting, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.
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