40 years and over with a reading add.

Control lens: Etafilcon A, Nelfilcon A, Nesofilcon A, Somofilcon A, 58% Poly-HEMA

Test lens: Etafilcon A

Up to 10 prototype contact lens designs and at least 1 commercially available contact lens designs will be worn by each participant for up to a week on a daily disposable modality. Participants will attend separate fitting and assessment visits for each lens type (Fitting Visit on Day 1, and Assessment Visit as late as Day 7, but may be as early as 6 hours after the Fitting Visit). There will be a minimum 1 night washout period between lens designs, i.e. after an assessment visit but before the next fitting visit.

18-39 years with no reading add.

Control lens: Etafilcon A, Nelfilcon A, Omafilcon A

Test lens: Etafilcon A

Up to 10 prototype contact lens designs and at least 1 commercially available contact lens designs will be worn by participants for up to a week on a daily disposable modality. Participants will attend separate fitting and assessment visits for each lens type (Fitting Visit on Day 1, and Assessment Visit as late as Day 7, but may be as early as 6 hours after the Fitting Visit). There will be a minimum 1 night washout period between lens designs, i.e. after an assessment visit but before the next fitting visit.

Prototype lens material

For each lens, visual acuity will be measured at distance with a computerised LogMAR chart and at near with a near LogMAR chart. Data will be summarised as means +/- standard deviations. No transformation is likely to be required. Visual acuity will be compared between each lens design and control lens types. The significance of lens design will be determined for each visit.

Repeated effects linear mixed model with subject random intercepts or paired t tests will be employed for the analysis of visual acuity. Analysis will be performed within each study arm namely presbyopes and non-presbyopes.

For each lens, subjective ratings of vision will be assessed with a questionnaire based on a 1 to 10 scale in steps of 1. The questionnaire has been designed specifically for this study. Data will be summarised as means +/- standard deviations. No transformation is likely to be required. Subjective ratings will be compared between each lens design and control lens types. The significance of lens design will be determined for each visit. Repeated effects linear mixed model with subject random intercepts or paired t tests will be employed for the analysis of subjective ratings. Analysis will be performed within each study arm namely presbyopes and non-presbyopes.