The answer to whether you can soak contact lenses in eye drops is a definitive no. Contact lens solutions and eye drops are fundamentally different products, each formulated for a specific purpose. A contact lens solution is designed to clean, disinfect, rinse, and safely store the lens, ensuring it is free of harmful microorganisms and deposits. Eye drops, on the other hand, are formulated to lubricate the eye, reduce redness, or deliver medication directly to the ocular surface. Attempting to use one product for the function of the other can lead to serious complications for both the lens and the eye.
Why Eye Drops Are Not a Substitute for Contact Solution
Contact lens solutions contain a complex blend of chemicals necessary for proper lens hygiene that eye drops lack. The primary difference is the presence of antimicrobial agents, which kill bacteria, fungi, and other pathogens that accumulate on the lens during wear. Eye drops, even those safe for use with contacts, do not contain these disinfecting ingredients, meaning a lens soaked in them remains contaminated.
Another element is the inclusion of surfactants and cleaning agents in contact solutions. These agents work to remove protein, lipid, and calcium deposits that build up on the lens material. Without these cleaning agents, which are absent in standard eye drops, the deposits remain and can contribute to discomfort and vision impairment.
The formulations also differ significantly in their chemical balance, specifically tonicity and pH. Contact lens solutions are carefully buffered to be isotonic, meaning their salt concentration matches the natural environment of the eye. This helps maintain the proper water balance within the lens material. If the lens is stored in a solution with an improper tonicity or pH, it can cause the lens to swell or shrink, altering its fit and potentially causing eye irritation.
The Primary Risks of Using Eye Drops
The most significant danger of substituting eye drops for contact solution is the severe infection risk. Without the active antimicrobial agents, the contact lens becomes a breeding ground for microorganisms. Bacteria, fungi, and the waterborne parasite Acanthamoeba can multiply rapidly on the lens surface.
Soaking the lenses in a non-disinfecting liquid dramatically increases the likelihood of developing microbial keratitis, a painful and potentially vision-threatening corneal infection. This occurs when pathogens trapped on the lens are held against the cornea. This condition requires intense medical treatment and can lead to permanent vision loss.
Improper storage also poses a direct threat to the delicate corneal tissue. The unremoved protein and lipid deposits left on the lens cause friction against the cornea and the inside of the eyelid. This repeated irritation can lead to corneal abrasions or inflammation, which compromises the eye’s natural defenses.
Furthermore, many eye drops, particularly medicated or redness-relieving types, contain ingredients that can physically damage the lens. These substances can cloud the lens material or cause it to degrade or warp. A compromised lens may also prevent the cornea from receiving adequate oxygen, leading to corneal edema or swelling.
Safe Temporary Storage Options
If you find yourself without contact lens solution, the safest course of action is to immediately remove your contact lenses and switch to glasses. If temporary storage is necessary, the only acceptable, though non-disinfecting, alternative is sterile, unpreserved saline solution. Saline is solely for rinsing and hydration; it will keep the lens wet but will not clean or disinfect it.
Any lens stored in saline or any liquid other than a fresh, multipurpose contact solution must be thoroughly cleaned and disinfected for the full recommended soaking time as soon as the proper solution is available. If you use daily disposable lenses, the safest choice is to discard them completely.
Under no circumstances should you ever use tap water, bottled water, saliva, or any homemade mixture to store your lenses. Tap water can contain Acanthamoeba, which causes a severe eye infection. Using any non-sterile liquids puts your vision at an unacceptable risk, and the only responsible action is to use pre-approved sterile saline or discard the lenses entirely.