Role of Corneal Nerves in Dry Eye Disease

Inclusion Criteria: * Group with DED: Diagnosis of DED based on the TFOS DEWS II report * Group without DED: No diagnosis of DED Exclusion Criteria: * Exclusion criteria: * Systemic disease that may affect ocular health and innervation * injury or history of operations on the anterior or posterior segment of the eye, which can affect the corneal structure and physiology * regular application of systemic or ocular medication known to affect the tear film except from DED medications * eye drops or makeup on the day of measurement. Remarks: Contact lens wearers are asked not to wear contact lenses for 1 week before the first appointment. Participant with DED medications will be asked to use only conservative-free eye drops on the days of examination