Eye drops are commonly used for conditions ranging from simple lubrication to managing complex diseases like glaucoma or treating infections. These drops deliver medication directly to the ocular surface. A frequent question is whether the eye should be rinsed with water or saline immediately after application. The general medical consensus is that routine rinsing is not recommended, as it directly interferes with the medication’s intended action.
Standard Use: Why Rinsing Is Counterproductive
Eye drops are formulated so active ingredients remain on the surface long enough to penetrate tissues. The goal is topical absorption, allowing the medication to work locally before the tear film naturally clears it away. Introducing water or saline immediately after application dilutes the concentration of the active compound.
This dilution effectively lowers the therapeutic dose, which can significantly reduce or negate the medication’s intended effect. The human eye can only hold about one drop of liquid at a time; any excess spills out or drains rapidly through the tear ducts. Rinsing accelerates this clearance process, washing away the drug before it has time to absorb into the corneal and conjunctival tissue.
Furthermore, the eye possesses a drainage system, the nasolacrimal duct, located in the inner corner near the nose. Excessive blinking or rinsing creates a pumping action that prematurely pushes the drug into this duct. Once in the nasolacrimal duct, the medication drains into the nasal cavity, where it is absorbed into the bloodstream, a process known as systemic absorption. This diversion reduces the amount of drug reaching the eye and can also increase the risk of systemic side effects throughout the body.
Proper Post-Drop Management
Since rinsing is discouraged, effective post-drop management focuses on maximizing contact time and minimizing drainage and overflow. After placing the drop, the user should close the eye gently for a specific period, typically between 30 and 60 seconds. This action prevents the drop from being pumped into the tear drainage system by avoiding rapid, forceful blinks that clear the ocular surface.
An even more effective technique is to apply gentle pressure to the inner corner of the eyelid, close to the bridge of the nose, immediately after the drop is applied and the eye is closed. This maneuver, called punctal occlusion, temporarily blocks the entrance to the nasolacrimal duct. Occluding the duct for up to a minute ensures the medication stays on the eye’s surface longer, enhancing its therapeutic effect while significantly reducing the amount that enters the bloodstream.
Any liquid that overflows onto the cheek or eyelids should be blotted away using a clean tissue. This wiping action must be done carefully, avoiding any contact with the eyeball itself or the immediate edge of the eyelid. The goal is simply to remove the residue that has spilled from the eye, not to wipe the drop off the ocular surface.
When Immediate Flushing Is Required
There are specific, urgent situations where immediate and thorough flushing of the eye is necessary for safety. If the eye has been exposed to a chemical splash, such as household cleaners, solvents, acids, or alkalis, flushing is mandatory. This immediate action helps dilute and wash away the corrosive material to minimize tissue damage.
Immediate flushing is also required if a severe, immediate adverse reaction occurs after using a drop, such as intense burning pain, sudden vision loss, or a severe allergic reaction with significant swelling. Should this occur, the protocol is to use clean water or sterile saline to flush the affected eye continuously for a full 15 minutes. The head should be tilted so the water flows away from the unaffected eye.
After or during the flushing process for chemical exposure or severe reaction, emergency medical attention must be sought immediately. Calling poison control or an emergency medical line is a necessary step to receive further guidance and professional care.