This study is intended to investigate the tolerability and the safety of Cyclosporine A containing CyclASol® eye drops compared to Placebo (vehicle) in a cohort of healthy volunteers. Subjects will be randomly assigned to dosing with CyclASol® eye drops or Placebo (vehicle) in the first part (first period) of the study, and switched to the alternative dosing in the second part (second period) of the study. An ophthalmological assessment of the eyes will be performed, and a questionnaire will be issued in the beginning and after each dosing. Additionally physical examinations, safety laboratory and ECGs will be performed, and blood samples will be analyzed for Cyclosporine A and Placebo (vehicle).

Inclusion Criteria:

• Healthy male or female subject aged 18 - 45 years
• Nonsmoker, for at least three months prior to first dose of trial medication
• BMI from 18.5 to 29.9 (kg/m2)
• Corneal/Conjunctival staining Oxford grading = 0°
• Schirmer I more than 10 mm/5min
• Tear Film Break-Up Time (TFBUT) equal or more than 10 s
• Intra-ocular pressure between 10 and 20 mmHg
• Normal funduscopy
• Subject will have given their voluntary written informed consent to participate in the study in their own language and are willing to comply with the protocol

Exclusion Criteria:

• History of clinically relevant allergy (except for untreated, asymptomatic, seasonal allergies at time of dosing)
• History of dry eye disease, ocular surgery, corneal disease
• Known hypersensitivity to the drug substance
• Limbal stem cell deficiency
• Cicatricial pemphigoid
• Glaucoma or known steroid response on intraocular pressure
• Ocular allergy or incompatibility against Ciclosporin or semifluorinated alkanes
• Punctual occlusion
• Corrected vision with glasses less than 0.7 on one or both eyes
• Contact lens wear 3 weeks before to the planned first drug administration and/or during the study
• Acute infection of ocular surface (bacterial, viral, fungal...)
• Acute trauma of ocular surface
• No acceptable methods of birth control
• Pregnancy or breast-feeding period (females only)
• Use of any drugs whatsoever (including vitamins and herbals) for fourteen (14) days prior to the planned first drug administration (excluding contraceptives in women and single use of paracetamol or ibuprofen)
• Topical or systemic therapy with steroids, Ciclosporin, non-steroidal anti- inflammatory drugs, tetracyclines or other immunomodulatory substances within last 90 days prior to the planned first drug administration or during this trial