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

This is a prospective, multi-center, subject-masked, bilateral wear, one month dispensing study comparing the clinical performance of the subjects' habitual comfilcon A sphere lens (control) following a refit with comfilcon A asphere lens (test). After the dispensing visit, subjects will return for follow-up evaluations after 2 weeks, and 1 month.

This is a prospective, multi-center, subject-masked, bilateral wear, one month dispensing study comparing the clinical performance of the subjects' habitual comfilcon A sphere lens (control) following a refit with comfilcon A asphere lens (test). After the dispensing visit, subjects will return for follow-up evaluations after 2 weeks, and 1 month.

Both comfilcon A sphere lens (control) and comfilcon A asphere lens (test) are Coopervison lenses.

Eligibility Criteria:
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)