This is a prospective, multicenter, open-label, randomized controlled trial designed to evaluate the efficacy and safety of perfluorohexyloctane (PFHO) eye drops (Hengqin®, Chengdu Shengdi Pharmaceutical Co., Ltd.) compared with 0.1% sodium hyaluronate eye drops in patients with video display terminal (VDT)-associated dry eye.

Participants aged 18-70 years with mild to moderate dry eye (confirmed by Chinese Dry Eye Expert Consensus 2020 criteria) who use video display terminal for more than 6 hours/day and at least 5 days/week for more than 1 year will be enrolled. A total of 159 subjects will be randomized in a 2:1 ratio to the experimental group (PFHO eye drops, n=106) or control group (0.1% sodium hyaluronate eye drops, n=53), both administered 1 drop/eye, 4 times daily (3-5 hour intervals), bilaterally, for 8 weeks.

The primary endpoint is the change from baseline in fluorescein tear film break-up time (FBUT) at Week 8. Secondary endpoints include FBUT changes at Weeks 2 and 4, standard patient evaluation of eye dryness（SPEED） questionnaire score changes, total corneal fluorescein staining (tCFS), partial blink rate (PBR), non-invasive tear film break-up time (NIBUT), lipid layer thickness (LLT), meibomian gland secretion quality score, and This is a prospective, multicenter, open-label, randomized controlled trial designed to evaluate the efficacy and safety of perfluorohexyloctane (PFHO) eye drops (Hengqin®, Chengdu Shengdi Pharmaceutical Co., Ltd.) compared with 0.1% sodium hyaluronate eye drops (Hialid®) in patients with video display terminal (VDT)-associated dry eye.

Participants aged 18-70 years with mild to moderate dry eye (confirmed by Chinese Dry Eye Expert Consensus 2020 criteria) who use electronic screens for more than 6 hours/day and at least 5 days/week for more than 1 year will be enrolled. A total of 159 subjects will be randomized in a 2:1 ratio to the experimental group (PFHO eye drops, n=106) or control group (0.1% sodium hyaluronate eye drops, n=53), both administered 1 drop/eye, 4 times daily (3-5 hour intervals), bilaterally, for 8 weeks.

The primary endpoint is the change from baseline in fluorescein tear film break-up time (FBUT) at Week 8. Secondary endpoints include FBUT changes at Weeks 2 and 4, SPEED questionnaire score changes, total corneal fluorescein staining (tCFS), partial blink rate (PBR), non-invasive tear film break-up time (NIBUT), lipid layer thickness (LLT), meibomian gland secretion quality score, and meibography score at Weeks 2, 4, and 8.

Inclusion Criteria:

1. Age 18-70 years (inclusive), male or female;

2. Subject reports dry eye symptoms for at least 6 months;

3. Diagnosis of mild to moderate dry eye according to the Chinese Dry Eye Expert Consensus (2020) criteria:

   • Mild dry eye: fluorescein tear film break-up time (FBUT) ≥2 seconds, no significant ocular surface damage signs, corneal fluorescein staining score <5;
   • Moderate dry eye: FBUT ≥2 seconds AND corneal fluorescein staining dots <30 or not exceeding 2 quadrants;

4. Normal tear secretion: Schirmer I test ≥10 mm/5 min;

5. Daily electronic screen usage >6 hours;

6. Electronic screen use for at least 5 days/week, for more than 1 year;

7. Understands and provides written informed consent.

Exclusion Criteria:

1. Allergy or hypersensitivity to any component of the study drugs;

2. Requires the use of artificial tears (other than study drug), secretagogues, ocular surface repair agents, anti-inflammatory/antibiotic eye drops, or other dry eye-related drugs (e.g., muscarinic receptor blockers for visual fatigue) during the study period;

3. Presence of any of the following ocular or systemic conditions:

   • Active ocular infection, ocular inflammation, or active ocular allergy;
   • Conjunctivochalasis, nasolacrimal duct obstruction;
   • Glaucoma or elevated intraocular pressure;
   • Retinal disease or ocular tumor;
   • Requirement to wear contact lenses during the study;
   • Obstructive sleep apnea syndrome or sleep disorders;
   • Planned or ongoing physical therapy (intense pulsed light, meibomian gland massage, warm compress, thermopulsation) within 2 weeks before enrollment through the end of study;

4. Ocular surgery within 3 months prior to enrollment, incomplete recovery from previous ocular surgery, or planned ophthalmic surgery during the study period;

5. Current smoker;

6. Pregnant or breastfeeding women, or women planning to become pregnant during the study period;

7. Uncontrolled systemic disease, or use of systemic medications (e.g., beta-blockers, benzodiazepines, corticosteroids, antihistamines, or other medications that may interfere with tear production);

8. History of anxiety or depression;

9. Any other condition that, in the judgment of the investigator, would make the subject unsuitable for participation.