When administering eye drops, which of the following is a crucial step to avoid contamination?

A. Shake the bottle before use: Shaking may be necessary for suspensions to ensure even distribution of medication, but it does not prevent contamination. While important for proper dosing, it is not the primary infection control measure. B. Administer while the patient is standing: The patient’s position affects comfort and ease of administration but does not influence contamination risk. Positioning can be adjusted to facilitate proper instillation into the conjunctival sac. C. Instill directly onto the cornea: Placing drops directly on the cornea can cause irritation or injury. Eye drops should be placed in the conjunctival sac, which does not reduce contamination risk but ensures safety and comfort. D. Do not touch the dropper tip to any surface.: Avoiding contact with the dropper tip prevents introduction of microorganisms that could contaminate the medication. Contaminated tips can cause eye infections, making this step crucial for safe administration.