Dispensing study to assess the visual performance of optimised prototype contact lenses

INTERVENTION: Multiple prototype contact lens designs made from etafilcon A material will be assessed during the study, where each design will be worn daily 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 on Day 7 at the latest, but may be as early as 6 hours after the Fitting Visit). There will be a minimum 24 hour washout period between lens designs, i.e. after an assessment visit but before the next fitting visit. Prototype lenses all have a multifocal design and each design will be available in +6 to ‐10 dioptre powers. The difference between the prototype designs are in their manipulation of higher order spherical aberrations via their optics (i.e. differing power distribution throughout the lens), in order to achieve an increased depth of focus. Different manipulations can achieve either different or similar depths of focus. Up to 25 contact lens designs will be tested in the study, however each individual participant will test a maximum of 10 prototype designs. However, as participants are able to withdraw at any time, the final number of lenses tested by each participant is essentially determined by them. Participants are asked to bring in any leftover lenses to the Assessment Visit as well as the foils of the lens blisters they open and use, to assist us in monitoring adherence. CONDITION: Presbyopia PRIMARY OUTCOME: Visual acuity, measured at distance with a computerised LogMAR chart and at near with a near LogMAR chart. SECONDARY OUTCOME: Subjective rating of comfort assessed for each pair of lenses with a questionnaire on a 1‐10 scale. The questionnaire has been designed specifically for this study. Subjective rating of vision will be assessed for each pair of lenses with a questionnaire based on a 1‐10 scale. The questionnaire has been designed specifically for this study. Willingness to purchase the lenses assessed with a yes/no response questionnaire. The questionnaire has been designed specifically for this study. INCLUSION CRITERIA: Able to read and comprehend English and give informed consent as demonstrated by signing a record of informed consent. Be at least 18 years old, male or female. Willing to comply with the wearing and clinical trial visit schedule as directed by the Investigator. Have ocular health findings considered to be “normal” and which would not prevent the participant from safely wearing contact lenses. Is correctable to at least 6/12 (20/40) or better in each eye with contact lenses. Be suitable and willing to wear contact lenses.