20 healthy participants will be evaluated for tolerability and safety of a new eye drop formulation for treatment of Dry Eye Syndromes, Oph1 0.5% Cyclosporine A (CsA) compared with Restasis 0.05% CsA ophthalmic formulation.

20 healthy participants will be enrolled to the study and randomized into two groups of 10 participants each. In one group participants will be treated with Oph1 0.5% CsA ophthalmic formulation and in the other group with Restasis 0.05% CsA ophthalmic formulation. Both groups will be treated with the eye drops in the right eye only, twice a day (6-9 hours apart), for four days and once on the fifth day (total of 9 eye drops treatment for each), both groups will have 2 days of washout, and will be crossed to identical course of treatment with the other ophthalmic formulation. All eye drops treatments will be done on the medical site by one of the study staff unblinded to the treatment. The Investigator assessing the ocular signs and the participants will be blinded to study treatment.

Inclusion Criteria:

1. Male or female aged 20-50 years, inclusive.
2. Systemically and ophthalmologically healthy subjects evaluated during the clinical history.
3. Best-corrected visual acuity (BCVA) 20/40 or better in both eyes.
4. Negative Fluorescein staining in Fluorescein Corneal staining (FCS) in both eyes.
5. Up to 0.5 Conjunctival redness in Conjunctival redness without slit lamp, in standardized lighting conditions, in both eyes.
6. IOP (< 22mmHg), in both eyes.
7. No pathology findings in Slit-lamp biomicroscopy in both eyes.
8. Ability to comply with the requirements of the study and complete the questionnaire and a full sequence of protocol-related evaluations.
9. Ability to understand and provide written informed consent.
10. In the judgement of the investigator, the participant can safely perform study activity.

Exclusion Criteria:

1. Have chronic systemic disease of any form known.
2. In the case of women: be pregnant, breastfeeding or planning to become pregnant within the study period or women without a history of hysterectomy, oophorectomy, who do not ensure a hormonal contraceptive method or intrauterine device during the study period.
3. Be a user of topical ophthalmic products of any kind.
4. Being a chronic drug user.
5. Be a user of contact lenses.
6. Have a history of any type of eye surgery.
7. Participating in clinical research studies 90 days prior to inclusion in the present study.
8. In the judgement of the investigator, any condition that could interfere with the intent of the study or would make participation not in the best interest of the participant.

Double blinded, participant and Outcome Assessors are blinded to the intervention