The INVIGORATE 2 Trial: A single-center, randomized, double-masked, crossover design, vehicle-controlled, Phase 3 clinical trial to assess the efficacy and safety of reproxalap ophthalmic solution (0.25%) compared to vehicle in subjects with seasonal allergic conjunctivitis using the environmental exposure chamber (EEC).

Inclusion Criteria:

• Be at least 18 years of age at the time of screening of either sex or any race;
• Provide written informed consent;
• Be willing and able to follow instructions, and can attend all required clinical trial visits.
• Have at least a two-year history of moderate-to-severe ragweed-induced allergic conjunctivitis based on investigator's judgement;
• Have a positive skin prick test to ragweed pollen within the past year of the Medical Screening Visit (Visit 1).

Exclusion Criteria:

• Have a history of blepharitis, dry eye syndrome, herpes simplex keratitis, or herpes zoster keratitis;
• Have systemic signs of infection (e.g., fever, current treatment with antibiotics).
• Have a systemic disease or uncontrolled medical condition, which, in the opinion of the investigator, could interfere with clinical trial measurements or subject compliance. Such diseases or conditions would include, but are not limited to, cancer, alcoholism, drug dependency or abuse, or psychiatric disease;
• Be a WOCBP who is pregnant, nursing, or not using an effective means of contraception;
• Have any known contraindication or hypersensitivities to any components of the Investigational Product (IP) drug formulation.