Contact lens wearers often experience dryness when the lens disrupts the eye’s natural tear film, leading to irritation and discomfort. Using standard over-the-counter solutions poses a significant risk because traditional drops are not designed to interact with the delicate material of contact lenses. This incompatibility can damage the lens structure or introduce harmful substances that become trapped against the cornea. Specialized products must be selected that work with the lens to restore moisture and comfort without causing adverse effects.
Understanding Compatibility and Preservatives
Soft contact lenses (typically hydrogel or silicone hydrogel) are designed to absorb and hold moisture. This absorptive property means the lens will draw in and concentrate any chemical components present in a drop. Many common artificial tears contain the preservative benzalkonium chloride, or BAK.
When BAK is absorbed by the contact lens, it accumulates over time, leading to complications. The concentrated chemical can cause the lens to cloud, resulting in blurred vision, and lead to chronic irritation of the eye’s surface. Prolonged exposure to BAK trapped in the lens can eventually damage corneal and conjunctival cells. Therefore, drops specifically formulated for contacts, or those labeled “preservative-free,” are preferred for frequent use, eliminating the risk of chemical buildup and ocular toxicity.
Types of Drops Safe for Contact Lenses
The safest and most common option for quick relief while wearing lenses are rewetting drops. These solutions are formulated to be isotonic and pH-balanced, matching the eye’s natural environment, and are engineered to simply moisten the lens surface and refresh the eye. They are thin, saline-based liquids that can be applied directly over the lens without causing cloudiness or altering the lens’s structure. Rewetting drops offer a temporary boost of hydration, making them ideal for occasional dryness throughout the day.
For more persistent dryness, a thicker lubricating or comfort drop may be necessary. These specialized artificial tears often contain high-molecular-weight polymers that provide a longer-lasting layer of moisture. Common lubricating agents include carboxymethylcellulose and sodium hyaluronate (hyaluronic acid), which has excellent water-retention capabilities. These ingredients increase the drop’s viscosity, allowing it to remain on the eye’s surface for an extended period to relieve chronic dry eye symptoms.
It is important to note that a multi-purpose cleaning and disinfecting solution should never be confused with a comfort drop. These cleaning solutions contain surfactants and disinfecting agents that are intended to be rinsed off the lens before insertion. Using a cleaning solution as an eye drop while the lens is in the eye will cause immediate and severe irritation due to the harsh chemical composition. Always confirm the product label states it is safe for use while wearing contact lenses.
Ingredients to Avoid
The category of eye drops that contact lens wearers must strictly avoid are redness relievers. These products contain vasoconstrictor chemicals, such as naphazoline or tetrahydrozoline, which work by constricting the tiny blood vessels in the conjunctiva, temporarily whitening the eye. If these chemicals are absorbed by the contact lens, they are held against the eye, which can lead to a condition known as “rebound redness.” Once the effect of the drop wears off, the blood vessels dilate excessively, causing the eye to appear redder than it was initially, often leading to dependency on the drops.
Contact lens wearers should also be cautious of drops containing oils. Some advanced artificial tears are formulated with mineral oil or castor oil to address the lipid layer of the tear film. While effective for the bare eye, these oil-based formulas can adhere to the surface of a soft contact lens, creating a permanent, cloudy film that blurs vision and necessitates discarding the lens. Always check the ingredient list for any oil or lipid component if the drop is not explicitly labeled as safe for use with contacts.
Application Guidelines and Medical Consultation
The proper application of contact-safe eye drops helps prevent contamination. First, thoroughly wash your hands before touching the eyes or the drop bottle. Hold the bottle above the eye, ensuring the tip does not make contact with the eye surface, lens, or eyelashes to maintain sterility. After instilling one or two drops, blink gently to evenly distribute the liquid across the lens and ocular surface.
Frequency of use depends on the formulation, but rewetting drops can generally be used several times a day as needed. If using a non-contact-safe drop, such as a prescription medication, the contact lenses must be removed first. A waiting period of at least 15 minutes is recommended before reinserting the lenses, allowing the medication to fully absorb. Persistent symptoms like unresolving redness, pain, or blurred vision that is not relieved by the drops require immediate consultation with an eye care professional.