The study will recruit 60 participants aged 60 and above, who suffered from insomnia for at least 3 months. Sleep parameters and chronotypes assessed with questionnaires and actigraphy, daytime sleepiness, and biological rhythm (dim light melatonin onset) will be measured. The intervention involves light exposure using a prototype device developed by GCSOL Tech Co., Ltd., a company with expertise in light therapy research and development. Three conditions will be tested (1) bright light; (2) near-infrared light; (3) bright light+ near-infrared light. Data analysis will employ paired t-tests to compare sleep parameters and dim light melatonin onset before and after treatment. Kruskal-Wallis tests and multivariate linear regression will be used to examine differences between intervention groups, controlling for gender and age. Safety analysis will include monitoring adverse events.

Inclusion Criteria:

• Pittsburgh Sleep Quality Index score is 8 or above.
• Early wakening ( 30 minutes before expected), or interruptted sleep for more than 30 minutes, lasting for more than 3 months.

Exclusion Criteria:

• Movement disorder, inability to move independently.
• Skin diseases, skin cancer, photosensitive skin diseases, or taking drugs that may cause photosensitivity (lithium salts, melatonin, antibiotics, A acid).
• Eye diseases such as glaucoma, diabetic retinopathy, and cataracts.
• Bipolar disorder.
• Light-induced epilepsy.
• Sleep disorders such as sleep apnea and involuntary leg twitching.
• Currently taking sedative-hypnotic drugs or receiving other non-drug treatments.
• Beck depression inventory-II score is greater than 13 points.
• Those who use cardiac rhythm regulators or artificial cardiopulmonary pacemakers.
• Acute illness.
• Abnormal blood pressure or fever.
• Pregnancy and pregnant women.
• Special physical abnormalities and sensory nerve abnormalities.
• Infectious diseases.
• Coagulation disorder.