Certified Ophthalmic Technician (COT) Practice Test 2025 - Free COT Practice Questions and Study Guide

Fluorescein staining is a crucial diagnostic tool for evaluating the integrity and function of the cornea. This test involves the application of a fluorescent dye to the surface of the eye, which highlights any areas of damage or irregularity on the cornea when viewed under a blue light. The presence of defects in the corneal epithelium will absorb the dye, allowing clinicians to assess issues such as abrasion, infection, or other corneal pathologies.

In contrast, the Schirmer test primarily measures tear production and does not provide direct information about corneal integrity. Tonometry is utilized to assess intraocular pressure and is critical in the diagnosis of glaucoma, but it does not specifically evaluate corneal health. Visual acuity tests measure how well a patient can see, which is more related to the clarity of the optical system and less about the condition of the cornea itself. Therefore, fluorescein staining stands out as the most appropriate choice for directly assessing corneal integrity and function.