Clinical Performance of Existing Wearers of Enfilcon A Following a Refit With Fanfilcon A Lenses for 4 Weeks

Inclusion criteria A person is eligible for inclusion in the study if he/she: * Is between 18 and 40 years of age * Has had a self-reported visual exam in the last two years * Is an adapted enfilcon A contact lens wearer (at least 2 weeks in enfilcon A lens) * Has a contact lens spherical prescription between -1.00 to - 6.00 * Has a spectacle cylinder up to 0.75D (Diopters) in each eye. * Can achieve best corrected spectacle distance visual acuity of 20/25 (0.10 logMAR) or better in each eye. * Can achieve a distance visual acuity of 20/30 (0.18 logMAR) or better in each eye with the study contact lenses. * Has clear corneas and no active ocular disease * Has read, understood, and signed the information consent letter. * Patient contact lens refraction should fit within the available parameters of the study lenses. * Is willing to comply with the wear schedule (at least 5 days per week, \> 8 hours/day assuming there are no contraindications for doing so). * Is willing to comply with the visit schedule Exclusion Criteria A person will be excluded from the study if he/she: * Is not a habitual wearer of enfilcon A lenses * Has a CL (Contact Lens) prescription outside the range of the available parameters of the study lenses. * Has a spectacle cylinder ≥1.00D of cylinder in either eye. * Has a history of not achieving comfortable CL wear (5 days per week; \> 8 hours/day) * Has contact lens best corrected distance vision worse than 20/25 (0.10 logMAR) in either eye. * Presence of clinically significant (grade 3-4) anterior segment abnormalities * Presence of ocular or systemic disease or need of medications which might interfere with contact lens wear. * Slit lamp findings that would contraindicate contact lens wear such as: * Pathological dry eye or associated findings * Pterygium, pinguecula, or corneal scars within the visual axis * Neovascularization \> 0.75 mm in from of the limbus * Giant papillary conjunctivitis (GCP) worse than grade 1 * Anterior uveitis or iritis (past or present) * Seborrheic eczema, Seborrheic conjunctivitis * History of corneal ulcers or fungal infections * Poor personal hygiene * Has a known history of corneal hypoesthesia (reduced corneal sensitivity) * Has aphakia, keratoconus or a highly irregular cornea. * Has Presbyopia or has dependence on spectacles for near work over the contact lenses. * Has undergone corneal refractive surgery. * Is participating in any other type of eye related clinical or research study.