Evaluation of Performance and Safety of Eye Drops With Hyaluronic Acid 0.30% and 0.15%

Inclusion Criteria:

Patients who meet all the following criteria at the screening/baseline visit will be considered as eligible for the investigation:

1. Patients having signed written informed consent to participate in the investigationobtained according to Good Clinical Practice (GCP);

2. Patients having an age ≥ 18 years;

3. Patients with diagnosis of dry eye syndrome (according to Tear Film and OcularSurface Society [TFOS] Dry Eye Workshop [DEWS] definition);

4. Diagnosis of dry eye syndrome for the investigation assessed through at least thefollowing exams: slit lamp examination (SLE), tear (lacrimal) meniscus exam,Schirmer's test I, TFBUT, cornea and conjunctiva staining, IDEEL questionnaire ("DryEye Symptom-Bother" module); 4a) Diagnosis of mild dry eye syndrome will be based onthe following criteria:

• TFBUT 7-10 sec

• Schirmer's test I 7-10 mm

• Fluorescein staining of the cornea and conjunctiva (NEI scale value) <7

• IDEEL questionnaire ("Dry Eye Symptom-Bother" module) score 40-50

• Patient not treated in the previous 15 days for dry eye syndrome 4b) Diagnosisof moderate to severe dry eye syndrome will be based on the following criteria:

• TFBUT < 7 sec

• Schirmer's test I < 7 mm

• Fluorescein staining of the cornea and conjunctiva (NEI scale value) ≥7

• IDEEL questionnaire ("Dry Eye Symptom-Bother" module) score >50

• Dry eye syndrome treatment permitted; no ophthalmic gel treatment permitted In case of bilateral dry eye syndrome, both eyes will be treated but only the worsteye, defined as the eye with the higher severity of impairment according to theInvestigator's judgment based on the above exams, will be considered for assessments (although both eyes will be treated). In the case of bilateral dry eye syndrome withboth eyes having the same level of impairment, the right eye will be considered forassessments by convention; In case of monolateral dry eye syndrome, both eyes willbe treated. Evaluations of both the eyes will be collected but only target eyeevaluations will be used for statistical analysis.

5. Patients being able to comprehend the full nature and the purpose of theinvestigation, including possible risks and side effects, and patients able tocooperate with the Investigator and to comply with the requirements of the entireinvestigation (including ability to attend all the planned investigation visitsaccording to the time limits), based on Investigator's judgment;

6. Female patients having a negative urine pregnancy test result at screening and usingan appropriate method of contraception for at least 30 days before inclusion andduring the whole investigation period, according to the definition of Note 3 of ICHM3 Guideline*, if females of childbearing potential (i.e., not permanentlysterilized - post hysterectomy or tubal ligation status - or not postmenopausal);

• Note: According to the definition of Note 3 of ICH M3 Guideline a highlyeffective method is defined as those which results in a low failure rate (i.e.less than 1% per year) when used consistently and correctly. Highly effectivebirth control methods include: combined (estrogen and progestogen containing)hormonal contraception associated with inhibition of ovulation (oral,intravaginal, transdermal); progestogen-only hormonal contraception associatedwith inhibition of ovulation (oral, injectable, implantable); intrauterinedevice (IUD); intrauterine hormone-releasing system (IUS); bilateral tubalocclusion; vasectomised partner; sexual abstinence.

Exclusion Criteria:

Patients who fulfil any of the following criteria at the screening/baseline visit will be excluded from the investigation:

1. Patients with mild dry eye syndrome that have used eye drops product in the 15 dayspreceding the screening/baseline visit. Patients with moderate to severe dry eye syndrome may have used treatment for dryeye syndrome in the 15 days preceding the screening/baseline visit, with theexception of gel compounds;

2. Patients under treatment with corticosteroids or antibiotics eye drops,hypotony-inducing products or any other therapy that, as per Investigator's opinion,could interfere with the assessment of the efficacy or incidence of adverse events;

3. Patients with presence or history of any systemic or ocular disorder, condition ordisease (with particular attention to malignancies and neuro-oncological diseases)that, according to Investigator's judgment, can interfere with the conduct of therequired investigation procedures or the assessment of the efficacy or theinterpretation of the investigation results or the incidence of adverse events;

4. Patients with glaucoma;

5. Patients that use therapeutic or refractive contact lenses;

6. Patients with hypersensitivity and/or allergy to any of the BLUgel A free or BLUyalA free ingredients;

7. History of ocular surgery in either eye, excluding corneal refractive or cataractprocedures, within 90 days of investigation enrolment;

8. Patients not being able to apply during the investigation any eye drops product;

9. Patients treated with antidepressant, antiepileptic, antihistamine, anticholinergicdrug;

10. Patients participating to another clinical study/investigation at the same time asthe present investigation or within 30 days;

11. Patients who have history of drug, medication or alcohol abuse or addiction