This an interventional study looking at two different sequences of pre-operative eye drops, to determine which order is more effective in reducing intraocular pressure with pupil dilation.

Twenty healthy participants will be separated into two groups of 10 volunteers each. In both groups, the participant's right eye will serve as a control with only Tropicamide/phenylephrine given. In one group of 10 participants the left eyes will receive Alphagan prior to Tropicamide/phenylephrine. In the other group of 10 eyes, the left eyes will have Tropicamide/phenylephrine administered prior to Alphagan. The investigator will observe the intraocular benefits of the addition of Alphagan over the Tropicamide/phenylephrine alone and determine if pre-treating is any better than post-treating. In addition, the investigator will monitor pupil response, as it is known that Alphagan may have some effect on the pupil dilation.

Inclusion Criteria:

• Healthy with no major medical conditions. Contact lens wear is ok but must be not worn on the day of the study

Exclusion Criteria:

• Diabetic, history of glaucoma
• history of iris trauma
• history of eye surgery except LASIK or Photorefractive keratectomy laser eye surgery
• Anisocoria
• pregnancy

The PI measuring pupil size will not know the subject assignment.