Clinical Principles, Testing, and Procedures

A CPOA runs this entire battery independently, between the case history and the physician's exam, and the physician trusts the resulting numbers without re-verifying most of them personally. That trust is earned by knowing, for each test, exactly what can quietly corrupt a reading — a wrong number that looks confident is more dangerous than an admittedly uncertain one. This domain carries half the exam for the same reason it fills half the clinical day.

Pupillary assessment. Check pupils before any drop touches the eye — a dilating agent abolishes the light reflex outright, and even a topical anesthetic's reflex tearing blurs everything tested afterward. Work in a dimly lit room with the patient fixating a distance target (a near target triggers accommodative miosis that has nothing to do with the light reflex under test), and bring the light in obliquely from below rather than straight down the visual axis. Record diameter in millimeters in both bright and dim illumination, note shape and briskness, and run the swinging-flashlight test — light held on each eye for a couple of seconds before swinging briskly to the other — to screen for a relative afferent pupillary defect (RAPD). A pupil that paradoxically dilates as the light arrives on it points to disease in that eye's optic nerve or retina, not simply a sluggish reaction.