To evaluate the effect of netarsudil (AR-13324) ophthalmic solution on aqueous humor dynamics relative to its placebo.

Inclusion Criteria:

1. Healthy adult male or female subjects at least 18 years of age.
2. Local area resident, existing patient or employee of Mayo Clinic.
3. Medically healthy subjects with clinically insignificant screening results.
4. Subjects with two normal (non-diseased) eyes.
5. Intraocular pressure between 14 and 21 mm Hg (inclusive) in each eye at screening.
6. Best-corrected visual acuity in each eye of +0.4 (20/50) or better.
7. Able and willing to give signed informed consent and follow study instructions.

Exclusion Criteria:

1. Chronic or acute ophthalmic disease including glaucoma, macular degeneration, uveitis clinically significant cataract.
2. Known hypersensitivity to any component of the formulation or to topical anesthetics.
3. Previous intraocular surgery, retina laser procedures or refractive surgery.
4. Myopia greater than -4.00 D spherical equivalent.
5. Hyperopia greater than +2.00 D spherical equivalent.
6. Ocular trauma within the past six months.
7. Evidence of ocular infection, inflammation, cystoid macular edema, clinically significant blepharitis or conjunctivitis, or a history of herpes simplex keratitis.
8. Ocular medication of any kind within 30 days of screening.
9. Any abnormality preventing reliable applanation tonometry of either eye.
10. Central corneal thickness less than 500 μm or greater than 600 μm.
11. Cannot demonstrate proper delivery of the eye drop.
12. Clinically significant systemic disease which might interfere with the study.
13. Participation in any investigational study within the past 30 days prior to screening.
14. Use of systemic medication that could have a substantial effect on intraocular pressure within 30 days prior to screening, or anticipated during the study.
15. Women of childbearing potential who are pregnant, nursing, planning a pregnancy, or not using a physician-supervised form of birth control for at least the last 2 months.