This is a multi-center, double-masked, placebo-controlled, randomized, parallel-group study. The total duration of the study is approximately 13 months. Approximately 225 presbyopic participants will be enrolled into the study.~Presbyopic participants aged 45 to 55 years are the primary age group in this study.~Screening and Baseline: Participants will be screened for eligibility followed by a baseline visit after which they will be randomized to receive either UNR844 (low, medium 1, medium 2, and high) or Placebo, dosed one drop in each eye twice daily, for 3 months and then will undergo a 9 month treatment holiday period.~Randomized subjects will attend the following study visits after baseline: at Week 2, Month 1, Month 2, Month 3, Month 4, Month 5, Month 6, Month 7, Month 8, Month 9, Month 10, Month 11 and Month 12.~The primary objective for the study is to characterize dose-response of UNR844 for change from baseline in binocular Distance-corrected Near Visual Acuity (DCNVA) at Month 3.~There are 3 secondary objectives:~Characterize dose response of UNR844 as measured by change from baseline in monocular DCNVA at Month 3~Assess the duration of effect using change in DCNVA after Month 3 with various dose concentrations of UNR844~Evaluate the efficacy of improving DCNVA in presbyopic participants, as measured by proportion of participants gaining at least 0.3 Logarithm of Minimum Angle of Resolution (logMAR) DCNVA at Month 3
Study of safety and efficacy of UNR844 in subjects with presbyopia.