clinical evaluation of two daily disposable contact lenses and a monthly replacement lens

Conditions: Myopia

Summary: the objective of the study is to compare the clinical performance of silicone hydrogel daily disposable contact lenses, conventional hydrogel daily disposable contact lenses and silicone hydrogel monthly replacement contact lenses.


Eligibility criteria:
inclusion criteria: * be no less than 18 and no more than 39 years of age. * sign written informed consent and investigator to record this on case report form (see separate document). * be willing and able to adhere to the instructions set out in the protocol. * own a cell phone and be willing to receive text messages during the day. * be an existing successful daily wear soft contact lens. for the purposes of this study this means wearing lenses for at least 6 hours per day, 5 days per week for the last month. * no extended wear in the last 3 months. * subjective refraction must result in a vertexed spherical contact lens prescription between -1.00 and -6.00d. * have refractive astigmatism less than or equal to 1.00d in both eyes. * achieve visual acuity of 6/9 (20/30) or better in each eye. * require a visual correction in both eyes (no monofit or monovision allowed). * does not require presbyopic correction (i.e. not using any presbyopic correction and measured add power of less than +1.00d). * have normal eyes with no evidence of abnormality or disease. for the purposes of this study a normal eye is defined as one having: * no amblyopia. * no evidence of lid abnormality or infection (including blepharitis/meibomitis). * no conjunctival abnormality or infection. * no clinically significant slit lamp findings (i.e. stromal edema, vascularization, infiltrates or abnormal opacities). * no other active ocular disease. exclusion criteria: * requires concurrent ocular medication. * clinically significant (grade 3 or 4) corneal stromal haze, corneal vascularization, tarsal abnormalities, bulbar hyperemia, limbal hyperemia, or any other abnormality of the cornea that would contraindicate contact lens wear. * clinically significant corneal staining (grade 3 in more than one corneal region per eye). * requires presbyopic correction (i.e. not using any presbyopic correction and measured add power of less than +1.00d). * has had refractive surgery. * has had eye injury/surgery within 8 weeks immediately prior to enrolment for this study. * abnormal lacrimal secretions. * pre-existing ocular irritation that would preclude contact lens fitting. * keratoconus or other corneal irregularity. * pmma(polymethyl methacrylate), hybrid or rgp(rigid gas permeable) lens wear in the previous 8 weeks. does not require presbyopic correction (i.e. not using any presbyopic correction and measured add power of less than +1.00d). * any systemic illness which would contraindicate lens wear or the medical treatment of which would affect vision or successful lens wear. * diabetic. * infectious disease (e.g., hepatitis, tuberculosis) or an immunosuppressive disease (e.g., hiv (human immunodeficiency virus)). * history of chronic eye disease (e.g. glaucoma or armd (age related macular degeneration)). * pregnancy, lactating or planning a pregnancy at the time of enrolment. * participation in any concurrent clinical trial or in last 30 days.