The discomfort associated with contact lens wear often centers on dryness, which significantly shortens comfortable wearing time. This sensation occurs because the lens sits atop the eye’s natural tear film, a delicate structure composed of oil, water, and mucus. The lens disrupts this stability, accelerating the rate at which the tear film evaporates. Understanding the factors contributing to this increased evaporation—including environment, habits, lens material, and biology—is the first step toward finding a solution.
How Your Environment and Habits Affect Lens Moisture
Prolonged use of digital screens is a major behavioral contributor to lens dehydration, as focused attention naturally reduces the rate of blinking. An average blink rate of about 15 times per minute can drop by more than 50% during tasks like reading or computer work. Reduced blinking means that the fresh layer of tear film, which lubricates the lens surface and removes debris, is not spread consistently, leading to dry spots that compromise comfort.
The physical environment also heavily influences tear evaporation, particularly conditions that feature low humidity or high airflow. Central heating, air conditioning, and forced-air systems dry out the ambient air, which then draws moisture rapidly from the exposed eye surface and the contact lens. Similarly, exposure to wind, whether outdoors or while driving, directly increases tear evaporation and can lead to lens desiccation. Dry or high-altitude climates further exacerbate this effect, making it difficult for the tear film to remain stable throughout the day.
Lens Materials and Care Routine Issues
The lens material plays a substantial role in maintaining moisture. Older hydrogel lenses and some modern lenses with high water content (over 50%) rely heavily on absorbing water. Paradoxically, in a dry environment, these high-water-content lenses act like a sponge, drawing moisture directly from the tear film and making the eye feel drier. Silicone hydrogel materials, the current generation of soft lenses, prioritize oxygen permeability, often allowing for lower water content and less moisture draw from the eye.
The care routine can unintentionally introduce irritation and dryness. Certain multipurpose solutions contain chemical preservatives, such as polyquaternium-1, which are absorbed by the lens material. When inserted, these preservatives leach onto the eye, causing chemical sensitivity or toxicity that manifests as discomfort. Furthermore, wearing lenses beyond their recommended replacement schedule allows proteins and lipids from the tear film to build up. This accumulation changes the lens’s surface wettability, causing it to dry out faster.
Physiological Factors Causing Dryness
Difficulty maintaining lens moisture often stems from underlying biological conditions affecting tear quality or quantity. Undiagnosed dry eye syndrome (DES) is a common cause, resulting from insufficient tear production (aqueous-deficient) or excessive evaporation (evaporative). A frequent cause of evaporative DES is meibomian gland dysfunction (MGD), where eyelid glands fail to produce the oily component of tears. This lipid layer slows evaporation, and its poor quality allows the watery tear layer to disappear too quickly.
Tear production naturally decreases with age, and hormonal fluctuations, such as those associated with menopause or the use of hormonal contraceptives, can also alter tear film stability. Certain systemic medications commonly used for other conditions can significantly reduce tear secretion as a side effect. These include antihistamines, decongestants, some antidepressants, and specific blood pressure medications like beta-blockers and diuretics. If a new medication coincides with a sudden increase in lens dryness, it suggests a systemic effect on the body’s moisture balance.
Actionable Steps to Relieve Dryness
Immediate relief for contact lens dryness often involves using rewetting drops specifically formulated for lens wearers. Choosing preservative-free artificial tears can minimize the risk of a toxic reaction on the ocular surface caused by chemical preservatives. Incorporating the “20-20-20 rule” into screen time—looking 20 feet away for 20 seconds every 20 minutes—encourages a more complete blink and helps maintain a healthy tear film.
Environmental adjustments, such as using a humidifier indoors or wearing large sunglasses outdoors to block wind, can reduce tear evaporation. Consulting with an eye care professional can determine if a switch in lens material is necessary, perhaps moving to a lower water content or a different silicone hydrogel design. If physiological factors are suspected, a comprehensive eye examination can diagnose conditions like MGD or DES, allowing for targeted treatments that improve lens comfort.