Effects of Transcranial Direct Current Stimulation (tDCS) in Chronic Corneal Pain

Inclusion Criteria (for all subjects):

1. Provide informed consent to participate in the study;

2. 18 to 65 years old;

Additional Inclusion Criteria for Subjects with Chronic Corneal Pain:

1. Corneal pain for six months or more;

2. Referral from a corneal specialist (Dr. Perry Rosenthal) with refractoriness to
conventional ophthalmologic treatments for corneal pain such as local topical
medications and soft bandage contact lenses;

3. Report a Visual Analogue Scale (VAS) for pain of 4 or greater in the previous 3
weeks;

Exclusion Criteria (for all subjects):

1. History of alcohol or substance abuse within the last 6 months as self-reported;

2. Diagnosis of any neurological diseases (such as epilepsy);

3. Episodes of seizures within the last 6 months;

4. Unexplained loss of consciousness

5. Use of carbamazepine or neuropsychotropic drugs

6. Contraindications to tDCS

- Metal in the head

- Implanted brain medical devices

7. Pregnant at time of enrollment