Comparing a Monthly Replacement Lens Versus a Daily Disposable Lens

Inclusion Criteria: Are 17 to 40 years of age and have full legal capacity to volunteer; Have read and signed an information consent letter; Are willing and able to follow instructions and maintain the appointment schedule; Are habitual daily wearers of spherical single vision soft contact lenses to correct for distance vision in each eye Are correctable to a visual acuity of 20/20 or better (in each eye) with sphero-cylindrical subjective refraction; Have an astigmatism of ≤ 0.75DC in subjective refraction; Can be fit with the study contact lenses with a power between -1.00 and -6.00DS; this translates to best corrected vision sphere refraction that vertexes to a CL power between -1.00 and -6.00 (inclusive) at screening visit. Demonstrate an acceptable fit with the study lenses. Exclusion Criteria: Have taken part in another clinical research study within the last 14 days; Are currently habitual wearers of toric, multifocal or monovision lenses. Have worn any rigid contact lenses in the past 6 months Are an extended lens wearer (i.e., sleeping with their lenses) Have a difference of ≥1.5 D in best vision sphere subjective refraction between eyes; Have amblyopia and/or distance strabismus/binocular vision problem; Have any known active ocular disease, allergies and/or infection; Have a systemic condition that in the opinion of the investigator may affect a study outcome variable; Are using any systemic or topical medications that in the opinion of the investigator may affect a study outcome variable; Have a known sensitivity to the diagnostic pharmaceuticals to be used in the study; Have undergone refractive error surgery or intraocular surgery; Are a member of CORE directly involved in the study.