This is a multicenter, randomized, double-blind, placebo-controlled Phase III clinical trial, enrolling 842 subjects with moderate to severe dry eye, who will be randomized at a 1:1 ratio to receive either 1% OT202 ophthalmic solution or vehicle control. The trial consists of screening, run-in, 8-week double-blind treatment period, and three long-term safety follow-up cohorts (10 weeks, 28 weeks, and 54 weeks), including 342 subjects for the 10-week follow-up, 350 subjects for the 28-week follow-up, and 150 subjects for the 54-week follow-up. Unblinding will be performed after the completion of double-blind treatment for all subjects, who will then receive open-label 1% OT202 ophthalmic solution uniformly. The co-primary efficacy endpoints are the change from baseline in Total Corneal Fluorescein Staining Score (TCSS) and Visual Analog Scale-Eye Dryness Score (VAS-EDS) at Day 56. Pharmacokinetic assessments will be conducted in 60 of the subjects assigned to the 54-weeks long-term safety follow-up. An interim futility analysis will be performed once approximately 30% of subjects complete the treatment period. Analysis of covariance (ANCOVA) will be utilized for efficacy statistical analyses. The primary objective is to evaluate the efficacy and safety of OT202 ophthalmic solution in the treatment of moderate to severe dry eye.