Salt water, or saline solution, is a mixture of salt and water used as a supportive cleansing measure for minor eye irritation or discharge associated with a mild infection. This solution flushes away debris and soothes discomfort; it is not a cure for serious infections. This information provides context on a common home practice and does not replace professional medical diagnosis or treatment. Serious eye infections require immediate medical attention to prevent potential vision loss.
Understanding the Role of Saline in Eye Care
Saline used for eye care should be an isotonic solution, meaning its salt concentration (approximately 0.9% sodium chloride) matches that of human tears. This concentration prevents the solution from irritating or stinging the delicate eye tissues, unlike plain water or overly salty solutions.
Applying an isotonic solution provides mechanical cleansing action, washing away discharge, irritants, and foreign material. This flushing clears the surface of the eye and eyelids, offering temporary relief from mild irritation. The sodium chloride itself does not possess germ-killing properties; its function is to create a sterile, soothing wash that supports the eye’s natural defenses.
Using a properly prepared saline wash maintains the integrity of the corneal surface. Solutions that are not isotonic can cause cells to swell or shrink, potentially leading to discomfort or damage.
Essential Steps for Preparing a Sterile Saline Solution
Homemade saline preparation carries a significant risk of contamination, potentially leading to severe infections like Acanthamoeba keratitis. Medical professionals strongly recommend using commercially prepared, sterile eye wash products instead. If a commercial wash is unavailable, extreme caution and meticulous hygiene are mandatory when preparing a homemade solution.
To achieve a near-isotonic concentration, combine one-half teaspoon of non-iodized salt with one cup (240 milliliters) of clean water. Use non-iodized salt because additives like iodine in table salt can severely irritate the eyes. Tap water must be sterilized by bringing it to a rolling boil for a minimum of 10 minutes to kill microorganisms.
Allow the boiled water to cool completely to room temperature before mixing with the salt; applying warm or hot solution near the eye can cause serious burns. Once the salt is dissolved, store the solution in a clean, airtight container that has also been sterilized.
The homemade saline solution must be discarded after 24 hours, even if refrigerated, as bacterial growth occurs rapidly once exposed to air. Preparing a fresh batch for each use is the safest practice to minimize the risk of introducing contaminants.
Safe Methods for Administering the Solution
Proper hand hygiene is the first step before administering the saline solution. Wash hands thoroughly with soap and water for at least 20 seconds to prevent transferring germs. Transfer the cooled, fresh solution into a sterile applicator, such as a clean eye dropper, a sterile cotton ball, or a dedicated eye wash cup.
When applying the wash, gently hold the eyelid open. Direct a slow stream of the solution from the inner corner of the eye toward the outer edge to flush discharge and debris away from the tear duct opening. Avoid touching the eye or eyelid with the applicator tip to maintain sterility and prevent injury.
If washing both eyes, use a fresh, sterile cotton ball or a new batch of solution for the second eye to prevent cross-contamination. The washing process should be gentle and brief, focusing only on the exterior surface of the eye.
Limit application to no more than three to four times per day to avoid excessive manipulation of the irritated eye. If irritation persists or worsens after one day of supportive cleansing, discontinue the home remedy and seek medical advice.
Recognizing When Salt Water is Not Enough
Saline provides temporary relief for minor irritation but cannot treat an established or serious eye infection. Several “red flag” symptoms indicate the problem requires professional medical attention beyond a home remedy.
Immediate medical consultation is necessary if you experience:
- A sudden and noticeable change in vision, such as blurriness or loss of sight.
- Severe or increasing pain in the eye, suggesting the infection is progressing.
- Photophobia, or extreme sensitivity to light.
- Persistent redness that does not improve after 24 hours of cleansing.
- Thick, yellow or green discharge that continues or worsens over 24 to 48 hours, indicating a bacterial infection.
- Swelling around the eye, the feeling of a foreign object being lodged in the eye, or a fever accompanying the eye symptoms.
Continuing to use saline when these severe signs are present can delay proper treatment and lead to serious complications.