Contact lenses disrupt the tear film, the fluid layer coating the eye, often leading to or worsening chronic dry eye disease. This condition causes irritation, grittiness, or stinging when the eye lacks sufficient tears or when tears evaporate too quickly. Selecting the right lens option is a primary step in mitigating this discomfort, as modern lens technology offers materials and designs engineered to maintain moisture.
How Lens Materials Affect Hydration
The composition of a soft contact lens directly influences how it interacts with the tear film and how comfortable it remains. Soft lenses are broadly divided into two material categories: hydrogel and silicone hydrogel. Hydrogel lenses are made from water-containing polymers that rely on their water content to transmit oxygen to the cornea. Silicone hydrogel lenses represent a technological advancement, incorporating silicone into the polymer structure. This silicone component is highly efficient at allowing oxygen to pass through the lens, even at a lower water content.
Traditional hydrogel lenses with high water content are paradoxically prone to drying out faster. As the lens loses moisture, it attempts to compensate by drawing water directly from the tear film, which increases dryness and discomfort. Silicone hydrogel lenses minimize this effect by relying less on water for breathability. Since the silicone allows more oxygen to reach the eye, the lens material can possess a lower water content, making it less likely to dehydrate.
Manufacturers further enhance comfort by applying surface treatments or embedding wetting agents. These agents create a hydrophilic surface that helps stabilize the tear film and maintain a moist environment.
Specialized Lens Designs for Dry Eye Relief
Beyond the material’s chemistry, the physical design and replacement schedule of a lens can significantly impact dry eye symptoms. Daily disposable lenses offer a distinct advantage for dry eye sufferers because they are discarded after a single use. This modality ensures the wearer starts each day with a fresh, sterile lens, eliminating the buildup of proteins, lipids, and allergens that accumulate over time on multi-use lenses and can exacerbate irritation and dryness.
For individuals with more pronounced or severe dry eye, specialized designs like scleral lenses are often recommended. These are large-diameter, rigid gas permeable (RGP) lenses that vault completely over the sensitive cornea and rest on the less-sensitive white part of the eye, known as the sclera. Before insertion, the bowl of the lens is filled with sterile saline solution, creating a continuous fluid reservoir between the lens and the corneal surface. This reservoir acts as a constant “liquid bandage,” providing continuous hydration and protection.
While standard RGP lenses, which are smaller and rest directly on the cornea, do not contain water and therefore cannot dehydrate, their rigid nature can be challenging for some patients to adapt to. Scleral lenses maintain the sharp vision quality of RGP materials while offering a unique hydration mechanism and greater comfort due to their larger size and resting point on the sclera.
Essential Practices Beyond the Lens
The choice of lens material and design is only part of a comprehensive strategy for managing dry eye with contacts. The solutions used to clean and store reusable lenses play a direct role in ocular comfort. Many multipurpose solutions contain preservatives that can cause sensitivity or irritation, especially for eyes already prone to dryness. Switching to a hydrogen peroxide-based cleaning system is often recommended, as these solutions are preservative-free and undergo a neutralization process, leaving behind only sterile saline.
Specific lubricating or rewetting drops are also formulated to be compatible with contact lens materials, helping to replenish the tear film throughout the day. These drops provide temporary relief by adding moisture without damaging the lens. Ultimately, selecting the appropriate lens and care routine requires a professional assessment. A qualified eye care professional must evaluate the individual’s tear film quality, measure the eye’s unique topography, and determine the optimal fit, material, and design based on the specific type and severity of dry eye symptoms.