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CompletedNCT06992635Updated Nov 20, 2025

Effect of Smart Phone Reflective Light Film on Dry Eyes and Asthenopia

An interventional study of using non-processing screens and using AR+CP screens in Dry Eye Disease (DED) and Asthenopia, sponsored by Second Affiliated Hospital, School of Medicine, Zhejiang University. Completed at 1 site in China. Open to participants aged 18 Years to 40 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-11-20.

Sponsored by Second Affiliated Hospital, School of Medicine, Zhejiang University · Not applicable, Interventional, and Treatment

From the registry’s dates

  • Registered 11 months after the study started (first participant enrolled Jun 2024, registered May 2025).
Phase
Not applicable
Study type
Interventional
Enrollment
120
Allocation
Randomized
Ages
18 Years to 40 Years
Sex
All
01

Study summary

This study aimed to evaluate the effect of anti-reflection (AR) and circularly polarized (CP) film on video display terminal (VDT) induced dry eye and asthenopia after limited time and close distance of visual tasks under light and dark environment, searching for new strategy for eye-protective electronic screen. The study was randomized, double-blind and controlled. Subjects were enrolled following the criteria: diopter of both eyes not exceeding -6.0D and anisometropia not exceeding 2.0D. and randomly divided into control, AR, AR+CP group in light or dark environment. Character searching, gaming and video tasks utilizing specific smartphones for totally 45 minutes were performed. Researchers measured the indexes of dry eye and asthenopia before and after tasks to evaluate impacts induced by VDT.

Read the detailed description

The inclusion criteria required volunteers to have myopia diopter not exceeding -6.00D, hyperopia not exceeding +2.0D, astigmatism not exceeding -2.00D, anisometropia between both eyes not exceeding 2.00D. The key exclusion criteria were as follows: (1)strabismus and amblyopia; (2)used eye drops within 1 week; (3)had undergone eye surgery within 6 months; (4)worn contact lenses within the last 2 weeks; (5)had serious eye discomfort in the last 7 days; (6)Breastfeeding or pregnant women and patients with severe systemic diseases, psychosis or dementia.

Subjects who met the criteria were divided into five groups. 3 groups using non-processing smartphone screen, anti-reflection screen and anti-reflection plus circular polarization screen read in light environment and 2 groups using non-processing screen and anti-reflection plus circular polarization screen read in dark environment. Subjects did not know the characteristics of the smartphones they use. Subjects met the requirements were randomly grouped. The subjects did not use video terminals such as mobile phones within 30 minutes before the study began.

During the whole experiment, light-group subjects were in a room with normal indoor ceiling light, correlated colour temperature 3904K, desktop illuminance 388.7lux, screen brightness about 150nit, while dark-group in environment illuminance 0.02lux, screen brightness about 6nit. Light source stability (working surface illuminance fluctuation) greater than 99% during the whole experiment, desktop range uniformity greater than 80%. Desktop matte treatment without special reflection, indoor air conditioning control temperature: 22-25 degrees Celsius, humidity: 50-70%RH. Users placed it on a fixed mobile phone stand (the angle and height of the mobile phone stand can be adjusted to make sure all subjects could see reflection of the lamp on ceiling behind them from the smartphone black screen state). All subjects' eyes are 40cm away from the mobile phone screen, and they sit on a chair of appropriate height and fixed position. Two groups of subjects would complete the following three tasks in definite order: 1) Character searching task (5 minutes) : Subject read a meaningless text on the screen, found all the target characters in it, and told researchers about the statistics; 2) Game task: Subject played one of several pre-installed games requiring high concentration and eye tracking for 20 minutes; 3) Video task: Subject watched the video Animal World with the mobile phone for 20 minutes. During the study period, subjects should not do any behavior unrelated to watching the screen for a long time (more than 1 minute). We evaluated the subjects' basic ocular data: best corrected visual acuity(BCVA), spherical equivalent(SE), subjective questionnaires including Ocular Surface Disease Index(OSDI), Computer Vision Syndrome Scale 17 (CVSS17); dry eye comprehensive analysis before and after the experiment respectively: tear meniscus height(TMH), noninvasive tear break-up time(NIBUT), fluorescein tear break-up time(FBUT), corneal fluorescein staining(CFS), Schirmer I tear secretion test; asthenopia related examination: High-frequency component(HFC) and blink frequency.

02

Conditions studied

  • Dry Eye Disease (DED)
  • Asthenopia
03

In context

Dry Eye Syndromes

1,366 studies on the registry are indexed under Dry Eye Syndromes; 207 are open to participants now.

This study's enrollment of 120 is above the median of 60 across 1,129 interventional studies indexed under Dry Eye Syndromes.

Browse Dry Eye Syndromes studies →

Lead sponsor

Second Affiliated Hospital, School of Medicine, Zhejiang University is the lead sponsor of 1,047 studies on the registry; 502 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 40 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • 1.have basic reading comprehension skills and to be older than 18 years old. 2.diopter of both eyes not exceeding -6.0D and anisometropia not exceeding 2.0D.

Exclusion criteria

Exclusion Criteria:

  • presbyopia or decreased regulation function, ocular inflammation and disease, worn contact lens within 1 month, history of eye surgery within 6 months, lactating or pregnant woman, have severe systemic diseases.
05

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Double (Participant, Investigator)
Enrollment
120 participants (actual)

Study arms

  • Sham comparator
    light condition

    use smartphone under light condition for 45 minutes

    Behavioral: using non-processing screens · Behavioral: using AR+CP screens

  • Experimental
    dark condition

    use smartphone under dark condition for 45 minutes

    Behavioral: using non-processing screens · Behavioral: using AR+CP screens

Interventions

  • Behavioralusing non-processing screens

    ask subjects to use non-processing screens

  • Behavioralusing AR+CP screens

    ask subjects to use AR+CP screens

06

What researchers measure

Primary outcomes

  1. Flourescence tear break-up time

    Drop a drop of physiological saline onto a sodium fluorescein test strip. Gently touch the middle of the conjunctiva of both lower eyelids of the examinee with the test strip respectively, and instruct the examinee to blink their eyes gently and look straight ahead. The examiner observed the tear film of the examinee with cobalt blue light under a slit lamp. The time of tear film rupture was the time from the examinee opening their eyes to the appearance of the first black spot on the tear film. Three TBUT tests were detected and recorded for each eye respectively, and the average and maximum values were taken.

    Time frame: 2 months

  2. HFC (high frequency component of accommodative fluctuation)

    The SCR mode of the ACOMOREF K-MODEL computerized optometer was adopted. The subjects were asked to keep a close eye on the image. The image distance was gradually moved from infinity to 1m, 60cm, and 30cm, and remained at each of the four distances for 20 seconds. The equipment would analyze and record the high-frequency fluctuations of the subjects' ciliary muscles, known as HFC. After the test of the first eye, Take a 20-second break to test the second eye.

    Time frame: 2 months

  3. non-invasive tear break-up time

    The Oculus ocular surface comprehensive analyzer was adopted. The examinees sat upright in front of the instrument and were asked to blink their eyes lightly and then look at the red marked object. The instrument automatically conducted ocular surface image analysis to obtain and record the first NIBUT and average NIBUT of the examinees

    Time frame: 2 months

Secondary outcomes

  1. tear meniscus height

    The Oculus ocular surface comprehensive analyzer was used. The person being examined sat upright in front of the instrument and was asked to blink their eyes slightly and then look at the red marked object. The instrument automatically analyzed the ocular surface images to obtain the lacrimal river height data

    Time frame: 2 months

  2. corneal fluorescein staining

    After character searching, gaming and video tasks utilizing specific smartphones for totally 45 minutes, CFS was measured.

    Time frame: 2 months

  3. computer vision symptom scale 17

    A subjective scale reflecting the symptoms of visual fatigue, including the occurrence frequency and intensity of 17 ocular and extraocular symptoms

    Time frame: 2 months

  4. Schirmer I test

    The subjects were tested under non-anesthetic conditions. A 5mm×35mm filter paper was placed in the conjunctival sac of the inner 1/3 of the lower eyelid, with the remaining part hanging over the skin surface. The subjects were asked to gently close their eyes. After 5 minutes, the length of the filter paper soaked by tears was measured and recorded.

    Time frame: 2 months

07

Study locations

1 site
  • The Second Affiliated Hospital Zhejiang University School of Medicine (SAHZU)
    Hangzhou, Zhejiang 310000, China
08

Timeline

Tracking since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reachedSimilar studies: half by the dot; the band is the middle halfHalf of similar studies reached it by the dot; the band is the middle half, from a quarter to three quarters

Ran from Jun 2024 to primary completion in Oct 2024, 4 months.

Of 199 non-industry interventional studies with no phase under Dry Eye Syndromes, half reached primary completion within 12 months of starting (the median), counting those still running; a quarter within 5 and three quarters within 25. This study's 4 months is below that.

Counting every sponsor, half of 312 studies reached it within 10 months; a quarter within 4 and three quarters within 18.

How these figures are worked out, and which studies are left out of them.

Registered
May 8, 2025
First posted
May 28, 2025
StartActual
Jun 1, 2024
Primary completionActual
Oct 30, 2024
CompletionActual
Oct 30, 2024
Last update
Nov 20, 2025
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Nov 20, 2025, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
09

Registry details

Key details

Study ID
NCT06992635
Responsible party
Sponsor
First posted
May 28, 2025
Start date
Jun 1, 2024
Primary completion
Oct 30, 2024
Completion
Oct 30, 2024
Last update
Nov 20, 2025

Oversight

FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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