Inclusion Criteria:  Males or females ≥ 12 years of age Ability to comply with all protocol-mandated procedures independently and to attend all scheduled office visits  Exclusion Criteria:  Clinically significant ocular disease as deemed by the Investigator (eg, glaucoma, corneal edema, uveitis, severe keratoconjunctivitis sicca) that might interfere with the study Unwilling or unable to discontinue use of contact lenses at screening until study completion Unwilling or unable to suspend use of topical medication at screening until study completion Ocular trauma, ocular surgery, or non-refractive laser treatment within the 6 months prior to screening Use of any topical prescription or over-the-counter (OTC) ophthalmic medications of any kind within 7 days of screening, with the exception of lid scrubs with OTC products (eg, OCuSOFT® lid scrub, SteriLid®, baby shampoo, etc.) Recent or current evidence of ocular infection or inflammation in either eye (such as current evidence of clinically significant blepharitis, conjunctivitis, or keratitis). Subjects must be symptom-free for at least 7 days prior to screening Closed or very narrow-angle that in the Investigator's opinion is potentially occludable if the subject's pupil is dilated Prior participation in a study involving the use of Nyxol for the reversal of mydriasis Known hypersensitivity or contraindication to α- and/or β-adrenoceptor antagonists Clinically significant systemic disease (eg, uncontrolled diabetes, myasthenia gravis, cancer, hepatic, renal, endocrine, or cardiovascular disorders) that might interfere with the study Participation in any investigational study within 30 days prior to screening Resting heart rate (HR) outside the normal range (50-110 beats per minute) at the Screening Visit. Hypertension with resting diastolic blood pressure (BP)>105 mmHg or systolic BP > 160 mmHg at the Screening Visit.