Applying eye drops, whether medicated treatments or lubricating solutions, is a precise process designed to deliver an active ingredient directly to the ocular surface. The primary goal is ensuring a sufficient concentration of the drug remains on the eye long enough to be absorbed and exert its therapeutic effect. The effectiveness of any eye drop highly depends on the technique used, making proper application a determining factor in treatment success. Understanding what to do immediately after the drop lands in the eye is a crucial part of this process.
Recommended Time and Proper Technique
The standard recommendation for keeping the eyes closed after drop instillation generally falls within a range of one to five minutes, though the specific duration may vary depending on the medication or the prescribing doctor’s instructions. Closing the eye gently prevents the drop from being immediately pushed out or washed away by the natural blinking reflex. Avoid excessive blinking or squeezing the eyelids tightly shut, as this action can pump the medication into the tear drainage system, reducing contact time.
A highly recommended technique to maximize drop retention is nasolacrimal occlusion. This involves pressing lightly on the inner corner of the eye near the nose bridge. Sustaining this light pressure for the recommended time closes off the tear duct opening. This simple physical action helps keep the medication concentrated on the ocular surface for absorption.
Before application, ensure proper hand hygiene to prevent introducing bacteria to the eye. Also, avoid touching the dropper tip to the eye, eyelid, or any other surface. This contact can contaminate the solution, compromising sterility and effectiveness.
The Science Behind Preventing Drainage
The eye’s anatomy includes a built-in drainage system designed to clear excess fluid and debris, which quickly clears away medicinal drops. The conjunctival sac, the small pocket that holds the tear film, can only comfortably hold about 7 to 10 microliters of liquid. Since a standard commercial eye drop typically dispenses 40 microliters or more, this volume disparity means a significant portion of the dose immediately spills out or is lost.
The remaining liquid is then rapidly cleared from the eye’s surface through the lacrimal drainage system, which connects the eye to the nasal cavity. This system, consisting of the tear ducts and the nasolacrimal duct, quickly channels the drop into the back of the nose and throat. If this drainage is not blocked, a vast majority of the drug dose, up to 80%, can be lost from the eye’s surface within minutes.
Proper closure and nasolacrimal occlusion serve two main scientific purposes: maximizing contact time and preventing systemic absorption. Slowing the drop’s movement into the duct allows the medication a longer duration to penetrate eye tissues. This technique also minimizes the risk of the drug entering the bloodstream via the highly vascularized nasal mucosa, which can lead to unwanted side effects elsewhere in the body.
When Instructions Change: Different Drop Formulations
The required closure time or technique may be modified depending on the specific product formulation. Standard aqueous solutions, which are thin and water-like, benefit most from the one-to-five-minute closure and occlusion technique to prevent rapid clearance. In contrast, formulations like gels, ointments, or suspensions are designed to have a higher viscosity, which naturally increases their residence time on the eye.
Viscous Formulations
Ointments, in particular, are semi-solid and melt upon contact with the warm ocular surface, creating a layer that can provide a longer contact time compared to a liquid drop. After applying a thicker product, a brief, gentle blink may be necessary to help disperse the formulation evenly across the eye. However, these formulations also often cause temporary blurred vision, which is a normal, expected part of the drug delivery.
Multiple Medications
When a treatment regimen requires the use of multiple different eye drops, a specific interval is necessary to prevent one medication from washing out the other. It is generally recommended to wait at least five to ten minutes between the application of different medications to ensure each one is properly absorbed.
Contact Lenses
Contact lens wearers should note that medicated drops should typically be applied after lenses are removed. A waiting period of at least fifteen minutes is often advised before reinserting them.