Inclusion Criteria:  Patients over 18 years of age who are undergoing a corneal laser refractive surgery after a medical indication by the Vissum ophthalmologist  Exclusion Criteria:  Pregnancy Piercings Fitzpatrick skin classification V and VI Autoimmune diseases Epilepsy Previous history of herpes or ocular pathology Pathological or suspicious corneal topography Treatment in the previous month with corticosteroids, antihistamines or topical vasoconstrictors.