Tear dysfunction, also known as Dry Eye Disease (DED) is frequently encountered in the clinical practice. It is a multifactorial disease of the ocular surface characterized by insufficient tear production, loss of homeostasis of the tear film, increased osmotic stress of the ocular surface, ocular discomfort and visual disturbance.

Hyaluronic acid (HA) is a linear heteropolysaccharide (glycosaminoglycan) with unique hygroscopic, rheological, and lubricating properties. HA is naturally found at the human ocular surface where it contributes to the ocular hydration and lubrication thanks to its capability to bind water molecules.Sodium hyaluronate (SH), the salt form of HA, is widely used in artificial tears to counteract dry eye symptoms by facilitating eyelid sliding and reducing its friction on the corneal-conjunctival surface.

Conventional HA-based eye drops contain linear HA. However, artificially cross-linked HA (CLHA) has several advantages over linear HA in alleviating dry eye symptoms. The increased viscoelasticity of CLHA results in a greater stability and a better resistance to the enzymatic degradation by hyaluronidase, while preserving all the properties of linear HA. Furthermore, chemical cross-linking of HA extends its permanence on the ocular surface, thus reducing the number of instillations and increasing patients' compliance.

For these reasons, an interventional, non-comparative, single-center Post Marketing Clinical Follow-up (PMCF) study was planned to evaluate the performance and safety of "Cross-Linked Hyaluronic Acid (CLHA)-based eyedrops" used as intended to improve lacrimal abnormalities, even when associated with dry eye symptoms.

The objectives of the PMCF study are confirmation of the performance, collection of additional safety data regarding expected adverse events and detection of potential unexpected adverse events associated with use of "Cross-Linked Hyaluronic Acid (CLHA)-based eyedrops" according to the Instructions for Use (IFU).

Each subject, after signing the Informed Consent Form (ICF), will enter the screening and baseline phase (the 2 visits will coincide) during which baseline procedures will be completed.

At baseline visit (V0), one of the "CLHA-based eyedrops" products will be administered to the enrolled subject.

The patient will perform 2 on-site visits: V0 and V2/EOS. To monitor the safety, 1 phone contact is planned (V1) to check for potential adverse events and concomitant medications intake.

Inclusion Criteria:

• Patient Informed consent form (ICF) signed;
• Male and Female Aged ≥ 18 years at the time of the signature of the ICF;
• Patients with dry eye symptoms and/or redness, fatigue, discomfort of the eye or the ocular mucosa due to intrinsic or extrinsic factors such as atmospheric agents, environmental factors, inflammation, blepharitis, eye surgery, and/or use of contact lenses;
• Willing not to use other eye drops during the entire treatment period.

Exclusion Criteria:

• Other - different - eyes clinical conditions (e.g. glaucoma);
• Suspected alcohol or drug abuse;
• Known hypersensitivity or allergy to Investigational Product (IP) components;
• Other clinically significant and uncontrolled pathologies that may interfere with study results (e.g. rheumatic diseases, diabetes);
• Participation in another investigational study;
• Inability to follow all study procedures, including attending all site visits, tests and examinations;
• Mental incapacity that precludes adequate understanding or cooperation.