One Month Dispensing Study Comparing the Clinical Performance of the Comfilcon A Sphere Lenses Compared to Comfilcon A Asphere Lenses.

Inclusion criteria A person is eligible for inclusion in the study if he/she: * Is between 18 and 34 years of age (inclusive) * Has had a self-reported eye exam in the last two years * Is an adapted comfilcon A sphere contact lens wearer * Uses digital devices, (e.g. computer, tablet, smart phone, iPad), for more than 4 hours a day, 5 days a week. * Has a contact lens spherical prescription between -1.00 to -6.00 (inclusive) * Has a spectacle cylinder no greater than 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. * Has a contact lens refraction that fits 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: * Has a history of not achieving comfortable CL (Contact Lens) wear (5 days per week; \> 8 hours/day) * Presents with clinically significant anterior segment abnormalities * Presents with ocular or systemic disease or need of medications which might interfere with contact lens wear. * Presents with slit lamp findings that would contraindicate contact lens wear such as: * Pathological dry eye or associated findings * Significant 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 (or history in past year) * Seborrheic eczema of eyelid region, 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. * Is habitually using rewetting/ lubricating eye drops (more than once per day)