Emergency Contact Lens Storage: How To Safely Preserve Lenses Without Multipurpose Solution

To safely preserve contact lenses without commercial multipurpose solution, store them temporarily in sterile saline solution or allow them to undergo dry storage if they are rigid gas permeable lenses. Never expose contact lenses to tap water, saliva, or homemade non-sterile liquids, as these mediums contain pathogenic micro-organisms that cause blinding corneal infections. Any lens stored in an emergency medium must undergo a complete six-hour disinfection cycle in a licensed multipurpose or hydrogen peroxide system before being reinserted into the eye.

Clinical Preparation & Emergency Inventory Assessment

In clinical contactology, running out of dedicated multipurpose disinfecting solution (MPS) constitutes a biological emergency. Contact lenses—specifically soft lenses made of hydrogel or silicone hydrogel materials like senofilcon A or comfilcon A—are highly hydrophilic polymer matrices. These matrices are engineered to exist in a state of osmotic equilibrium with human tears, which maintain a constant osmolarity of approximately 290 to 310 mOsm/L.

Introducing lenses to non-sterile or non-isotonic environments alters the structural alignment of the polymer, compromises oxygen permeability (Dk/t), and invites rapid bacterial colonization by opportunistic pathogens such as Pseudomonas aeruginosa and Acanthamoeba trophozoites.

Before attempting any emergency preservation, you must assess your environment and gather the safest available tools to minimize ocular risk.

Emergency Storage Checklist

• Essential Preservation Mediums: Commercial sterile saline solution (preservative-free or buffered), unit-dose artificial tears (without active redness-relievers), or distilled water combined with pure sodium chloride (emergency protocol only).
• Sterile Hardware: An airtight, clean contact lens case. If unavailable, use a boiled glass vessel or a sterile, food-grade polyethylene container.
• Sanitization Agents: Isopropyl alcohol (70% or higher) or antibacterial soap free of heavy perfumes and moisturizing oils.
• Mandatory Prerequisite Knowledge: Precise identification of lens material (Soft vs. Rigid Gas Permeable) and a strict understanding of the ocular risks associated with water-borne pathogens.
• Estimated Budget: $0 to $15.
• Safe Storage Duration Limit: Maximum of 12 to 18 hours before structural degradation or pathogenic risk renders the lenses unwearable.

Medical Protocols for Emergency Contact Lens Preservation

Step 1: Identify and Segment Your Lens Material Class

Before initiating any emergency storage protocol, you must determine whether your contact lenses are Soft (hydrogel/silicone hydrogel) or Rigid Gas Permeable (RGP).

1. Inspect the physical flexibility of the lens. If the lens is highly pliable, folds easily between your fingertips, and has a high water content (typically 38% to 74%), it is a soft lens. Soft lenses must remain hydrated to retain their shape and refractive power.
2. If the lens is rigid, small (typically 8.0 to 9.5 mm in diameter), and maintains its dome shape under moderate lateral pressure, it is an RGP lens. RGP lenses are structurally stable and can safely withstand dry storage without permanent warping.

Warning: Never attempt dry storage with soft hydrogel lenses unless you are prepared to potentially discard them. If a soft lens dries out completely, the polymer matrix collapses, making the lens brittle. While it can sometimes be rehydrated, the structural integrity is often permanently compromised, increasing the risk of corneal micro-tears upon re-insertion.

Step 2: Sourcing and Deploying Sterile Commercial Saline

If multipurpose solution is unavailable, sterile commercial saline is the only clinically acceptable liquid alternative. Sterile saline is 0.9% sodium chloride (NaCl) dissolved in purified water, matching the osmotic pressure of the human cornea.

1. Thoroughly wash your hands with non-cosmetic, antibacterial soap for a minimum of 30 seconds. Dry your hands using a lint-free microfiber towel to prevent fiber transfer to the lens.
2. Clean your contact lens case. If you have no fresh solution to rinse it with, wipe the wells with 70% isopropyl alcohol and allow them to air-dry completely for 10 minutes to ensure any viral or bacterial pathogens are destroyed.
3. Fill the clean wells of the case with sterile commercial saline solution. This is often found in first-aid kits as eye wash or wound irrigation solution.
4. Remove your lenses carefully and submerge them fully in the saline. Seal the caps tightly.

Pro-Tip: Sterile saline does not possess antimicrobial or disinfecting properties. It serves solely as a holding medium to prevent osmotic shock and warping. You must disinfect these lenses in a standard multipurpose solution for at least six hours before placing them back on your eyes.

Step 3: Executing Dry Storage (Best Practice for RGP Lenses)

If you wear Rigid Gas Permeable (RGP) lenses and have no solution, dry storage is the safest, most clinically sound option. It completely eliminates the risk of water-borne pathogen proliferation.

1. Perform the standard hand hygiene protocol.
2. Sterilize your lens case by wiping the interior with isopropyl alcohol and waiting for it to dry. Do not rinse the case with tap water.
3. Remove the RGP lenses from your eyes. Use a clean, dry lint-free tissue to gently blot away residual tear film from the surface of the lenses.
4. Place the dry RGP lenses directly into the dry wells of the case and seal them.
5. Prior to re-wearing, fill the case with standard RGP conditioning/wetting solution and allow the lenses to soak for at least 4 hours to re-establish the surface hydrophilic layer.

Step 4: Constructing Emergency Isotonic Saline (Last-Resort Protocol)

If you are stranded without access to sterile saline, commercial solution, or replacement lenses, you may construct a temporary, homemade isotonic saline solution. This must be treated as a high-risk emergency measure only.

1. Measure exactly 100 milliliters of distilled water. If distilled water is unavailable, use bottled drinking water. Do not use tap water or well water.
2. Boil the water in a clean, covered stainless steel pot for at least 15 minutes. This thermal processing kills vegetative bacterial cells, though it may not destroy all thermophilic bacterial spores.
3. Add exactly 0.9 grams of pure, non-iodized sodium chloride (fine table salt without anti-caking agents or preservatives). This ratio creates a 0.9% solution, which is isotonic to the human tear film.
4. Stir the mixture with a sterilized metal spoon until the salt is completely dissolved.
5. Allow the solution to cool to room temperature (approximately 20°C to 22°C / 68°F to 72°F). Do not place hot solution on your lenses, as high temperatures permanently melt and warp hydrogel polymers.
6. Pour the cooled solution into your sterilized lens case, insert the lenses, and seal.

Warning: This homemade solution is not sterile in a medical-grade sense. It lacks the buffering agents required to maintain a stable pH. Use this method only to keep your lenses from drying out overnight, and discard the lenses immediately if you experience any ocular redness or irritation the next day.

Step 5: Post-Emergency Disinfection and Rehydration

Before any lens that has been stored in emergency saline or a dry state can be safely worn, it must undergo a rigorous decontamination process to eliminate any micro-organisms that colonized the lens during storage.

1. Remove the lenses from the emergency medium. Discard the emergency fluid immediately and sanitize the storage case.
2. Place each lens in the palm of your hand. Apply 3 to 4 drops of fresh, commercially produced multipurpose contact lens solution.
3. Gently rub both sides of the lens with your index finger in a linear, radial motion (from the center outward) for 20 seconds. Do not rub in circular motions, as this can tear the thin edges of silicone hydrogel lenses.
4. Rinse the lens thoroughly with a steady stream of fresh multipurpose solution to flush away loosened surface lipids, proteins, and microbial contaminants.
5. Fill your sanitized lens case with fresh, unused multipurpose solution or place the lenses in a neutralizer-supported hydrogen peroxide disinfection cup.
6. Allow the lenses to soak for a minimum of 6 hours. This timeframe is required for standard biocides (such as polyaminopropyl biguanide or polyquaternium) to penetrate the polymer matrix and destroy stubborn pathogens.

Technical Performance of Emergency Storage Mediums

Troubleshooting Emergency Storage Failures and Contamination Scenarios

Scenario 1: Soft Contact Lens Dried Out and Adhered to Case

• Root Cause: The temporary emergency liquid evaporated or leaked, causing the hydrophilic polymer matrix of the soft lens to lose its water content. The dehydrated polymers bonded directly to the plastic surface of the contact lens case.
• Actionable Fix: Do not attempt to peel, pull, or scrape the dry lens from the case, as this will tear the material. Fill the lens case well completely with fresh commercial multipurpose solution. Let the lens sit undisturbed for a minimum of 4 hours. The lens will slowly absorb the saline, swelling back to its original shape and releasing its bond from the plastic. Once detached, inspect the lens under a bright light for edge tears or cracks. If any physical deformities are visible, discard the lens immediately.

Scenario 2: Accidental Exposure to Tap, Lake, or Pool Water

• Root Cause: The contact lenses were stored in tap water overnight, or worn while swimming, allowing Acanthamoeba cysts to attach to the porous lens surface. These cysts can penetrate the corneal epithelium, leading to severe keratitis.
• Actionable Fix: Do not put the lenses back in your eyes under any circumstances. If you have already inserted them, remove them immediately. Discard the contaminated pair of lenses. Flush your eyes with sterile saline or artificial tears. If you experience pain, blurred vision, or light sensitivity within 48 hours of exposure, schedule an immediate emergency examination with an optometrist or ophthalmologist.

Scenario 3: Intense Ocular Burning or Pain Upon Re-insertion

• Root Cause: The emergency storage solution had an incorrect pH or salt concentration (hypertonic or hypotonic), or the lens was re-inserted without removing residual, non-buffered DIY saline or chemical contaminants.
• Actionable Fix: Remove the contact lenses immediately. Flush your eye with sterile, preservative-free artificial tears or sterile saline to restore your eye's natural pH. Place the lenses back into a commercial contact lens case filled with fresh multipurpose solution. Allow your eyes to rest for at least 2 hours. If the burning sensation, redness, or excess tearing persists, discard the lenses and seek medical advice.

Frequently Asked Questions

Can I use saliva to store or lubricate my contact lenses in an emergency?

No, you must never use saliva on contact lenses. The human mouth contains billions of anaerobic and aerobic bacteria, including Streptococcus and Staphylococcus species, which can cause rapid, aggressive bacterial corneal ulcers and permanent vision loss.

Are artificial tears or rewetting drops safe for overnight contact lens storage?

Yes, sterile, preservative-free artificial tears or contact lens rewetting drops can serve as a temporary overnight holding medium. However, because they contain high concentrations of viscosity agents, they will leave a thick film on the lens, requiring you to thoroughly clean and disinfect the lenses with multipurpose solution before wearing them again.

How long can a contact lens survive dry without solution?

Rigid Gas Permeable (RGP) lenses can survive dry indefinitely without damage. Soft hydrogel lenses can survive dry for several days, but the longer they remain dehydrated, the more brittle they become, which often results in microscopic fractures in the polymer matrix that make them unsafe to wear.

What actually happens if I use tap water to store my contacts overnight?

Tap water contains microscopic organisms and lacks the necessary salt concentration of your natural tears, which causes soft contact lenses to absorb water, swell, and lock onto your cornea. Additionally, water-borne pathogens like Acanthamoeba can easily trap themselves between the lens and your eye, leading to serious corneal infections that are difficult to treat.

Schedule a Comprehensive Eye Health Evaluation

Protecting your eyes from corneal infections requires proper lens care and regular assessments of your ocular health. Contact our optometric clinic today to schedule a comprehensive eye exam and discuss the safest daily wear options for your lifestyle.