The purpose of this research study is to understand the mechanism of action of low level light therapy and also potentially yield markers associated with good treatment response. Low-level light therapy is light-based treatment delivered through advance eye-light device. This therapy uses light energy to provide energy to the meibomian gland cells to slow down age-ing, improve tear stability and reduce inflammation.

Inclusion Criteria:

1. Must be eligible for, and have consented for low level light therapy
2. Must not have presented to the clinic for an acute eye problem such as visual loss or painful eye
3. Ability to give informed consent.
4. Age more or equals to 21 years old.

Exclusion Criteria:

1. Patients who are unable to or decline to give consent.

2. Age less than 21 years old.

3. Patients who presented to the clinic for an acute eye problem such as visual loss or painful eye.

4. Patients not suitable for low level lighttherapy:

   • Pregnant
   • Fitted with pacemakers, metal, electrical, acoustic prosthetics
   • Epilepsy, cardiac rhythm or frequency disorders
   • Fever, thrombophlebitis or acute phlebitis of the legs, large-sized varicose veins, or venous surgery within 2 months
   • Uncontrolled hypertension or severe diabetes
   • Open wounds on eyelid or skin
   • Evolving cancer or hepatitis
   • Blood anticoagulant or coagulation defect

Patient undergoing low level light therapy that met the study inclusion and exclusion