The objectives of this study are:

• To evaluate the safety of Nyxol in pediatric subjects
• To evaluate the efficacy of Nyxol to expedite the reversal of pharmacologically induced mydriasis in pediatric subjects The Sponsor intends to use this study to evaluate Nyxol in pediatric subjects aged 3 to 11 for the indication "the treatment of pharmacologically induced mydriasis produced by adrenergic (phenylephrine) or parasympatholytic (tropicamide) agents, or a combination thereof."

This is a randomized, parallel-arm, double-masked, placebo-controlled study in approximately 20 randomized pediatric subjects evaluating the safety and efficacy of Nyxol in pediatric subjects with pharmacologically induced mydriasis with three dilating agents (e.g., phenylephrine, tropicamide, and Paremyd). Pediatric subjects will be recruited for the study into 2 age groups as follows:1) 3 to 5 years of age: 10 subjects 2) 6 to 11 years of age: 10 subjects.

Inclusion Criteria:

1. Males or premenstrual females 3 to 11 years of age
2. Ability to comply with all protocol-mandated procedures independently and to attend all scheduled office visits
3. Parent/Legal guardian willing to give written informed consent to participate in this study. Children aged 7 to 11 years to provide signed assent form, as well as a separate parental/legal guardian consent.

Exclusion Criteria:

1. Clinically significant ocular disease as deemed by the Investigator(eg, amblyopia, congenital cataract, congenital glaucoma) that might interfere with the study

2. Unwilling or unable to discontinue use of contact lenses at screening until study completion

3. Unwilling or unable to suspend use of topical medication at screening until study completion

4. Ocular trauma or ocular surgery within the 6 months prior to screening

5. Use of any topical prescription or over-the-counter (OTC)ophthalmic medications of any kind within 7 days of screening

6. 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

7. Closed or very narrow-angle that in the Investigator's opinion is potentially occludable if the subject's pupil is dilated

8. History of any traumatic (surgical or nonsurgical) or non-traumatic condition affecting the pupil or iris

9. Known allergy, hypersensitivity, or contraindication to any component of the phentolamine ophthalmic solution or to any component of the mydriatic agents or vehicle formulation

   Systemic:

10. Known hypersensitivity or contraindication to α- and/or β-adrenoceptor antagonists

11. Clinically significant systemic disease (eg, uncontrolled diabetes, cancer, hepatic, renal, endocrine, or cardiovascular disorders) that in the opinion of the Investigator could interfere with the study

12. Subjects with learning disabilities that in the opinion of the investigator could interfere with the study

13. Initiation of treatment with or any changes to the current dosage, drug, or regimen of any systemic adrenergic or cholinergic drugs within 7 days prior to screening or during the study(Appendix 4)

14. Participation in any investigational study within 30 days prior to screening