This study evaluated the effects of gac fruit oil supplementation on visual health, sleep quality, depressive symptoms, cognitive function, and brain imaging parameters in adults with sleep disturbance. Participants aged 40 to 65 years were recruited and received gac fruit oil capsules for 30 days. The supplementation protocol consisted of two capsules in the morning and two capsules in the evening each day. Assessments were performed before and after the intervention, including macular pigment measurement, ocular surface disease evaluation, tear film analysis, contrast sensitivity testing, accommodative microfluctuation analysis, optical coherence tomography, the Pittsburgh Sleep Quality Index, a depression scale, the Mini-Mental State Examination, and brain magnetic resonance imaging. The study aimed to explore whether 30 days of gac fruit oil supplementation was associated with changes in visual function, sleep quality, mood-related measures, cognitive function, and brain imaging findings.

Inclusion Criteria:

• Adults aged 40 to 65 years.
• Participants with sleep disturbance.
• Participants who were willing to participate in the study and provide written informed consent.

Exclusion Criteria:

• History of ocular surgery.
• Cataract.
• Glaucoma.
• Current supplementation intended to increase macular pigment level.
• Pregnancy.
• Severe illness.
• Use of medications that may affect or stimulate sleep.
• Use of medications that promote sleep.
• Unable to undergo magnetic resonance imaging, including but not limited to individuals with a pacemaker, artificial heart valve, metal aneurysm clip, metallic tracheostomy tube, possible metallic fragments in the orbit, cochlear implant, implanted electrodes, neurostimulator, implanted drug infusion device, hemostatic clips, vascular stents, claustrophobia, previous brain surgery, or history of traumatic brain injury with implanted metal materials.
• Participants who experienced discomfort during the study or wished to withdraw could discontinue participation at any time without providing a reason.

Individual participant data will not be shared because the study data include health-related questionnaire responses, ophthalmic examination data, and brain magnetic resonance imaging data. Data were collected under the informed consent and confidentiality procedures approved by the institutional review board.