Evaluation of the Efficacy and Safety of DM05 Versus Optive™ on the Treatment of Moderate to Severe Ocular Dryness

Inclusion Criteria: * Sex: male or female. * Age: more than 18 years. * Subject with a dry eye syndrome needing artificial tears in the 3 months preceding the inclusion. * Subject having used only artificial tears without preservative (NaCl 0.9%, Hydrabak®) during 1 or 2 weeks before inclusion (at 3 drops per day). * Diagnosis of moderate to severe ocular dryness defined by a score OSDI (Ocular Surface Disease Index) ≥18. * Subject with at least one eye with: * Global ocular staining (cornea and conjunctiva) ≥4 and ≤9 (Oxford scale from 0 to 15) AND one the following criteria: * Schirmer test ≥ 3mm/5 min and ≤9mm/ 5 min OR * Sum of 3 measurements of Tear film Break-Up Time (TBUT) ≤ 30s. * Subject, having given freely and expressly his/her informed consent. * Subject who is able to comply with the study requirements, as defined in the present protocol, at the Investigator's appreciation. * In France: subject being affiliated to a health social security system. * Female subjects of childbearing potential should use a medically accepted contraceptive regimen since at least 12 weeks before the beginning of the study, during all the study and at least 1 month after the study end. Exclusion Criteria: * Pregnant or nursing woman or planning a pregnancy during the study. * Subject deprived of freedom by administrative or legal decision. * Subject in a social or sanitary establishment. * Major subject who is under guardianship or who is not able to express his consent. * Subject being in an exclusion period for a previous study. * Subject suspected to be non-compliant according to the Investigator's judgment. * Subject wearing contact lenses during the study. * Far best corrected visual acuity \< 1/10 * Subject with severe ocular dryness with one of these conditions: * Eyelid or blinking malfunction * Corneal disorders not related to dry eye syndrome * Ocular metaplasia * Filamentous keratitis * Corneal neovascularization * Subject with severe meibomian gland dysfunction (MGD) * Within the last 3 months prior to the inclusion, history of ocular trauma, infection or inflammation not related to dry eye syndrome. * Within the last 12 months, history of ocular allergy or ocular herpes. * Refractive or cataract surgery within the last 6 months. * Any laser other than refractive surgery within the last 3 months. * Any troubles of the ocular surface not related to dry eye syndrome. * Ocular hypertension or glaucoma needing an hypotonic treatment * Subject having used artificial tears in the 6 hours preceding the inclusion visit. * Use during the month preceding the inclusion or during the study of: isotretinoïd, cyclosporine, tacrolimus, sirolimus, pimecrolimus, punctual plugs. * Any not stabilized systemic treatment, which can have an effect on performance or safety criteria, at the investigator appreciation.