The feeling of dry contact lenses is primarily caused by a disruption to the delicate tear film, a three-layered structure of oil, water, and mucus that coats the eye’s surface. The presence of a contact lens can interfere with this film, causing tears to evaporate too quickly or to be of insufficient quality. This prevents the lens from staying hydrated and the eye from remaining comfortable. Understanding the sources of this dryness is key to finding a lasting solution for comfortable lens wear.
Causes Related to Lens Management
The physical properties and maintenance of the contact lens itself can cause dryness. Lenses require moisture to remain soft, and some materials draw this moisture directly from the eye’s tear film. Older hydrogel lenses rely heavily on water content and may dry out quickly, pulling fluid from the eye’s surface as they dehydrate. Newer silicone hydrogel materials permit greater oxygen flow but can accumulate deposits more easily, leading to discomfort.
An improper lens fit is another factor. A lens that is too tight restricts the natural exchange of tears beneath it, while a loose lens moves excessively, causing friction. This mechanical irritation disrupts the tear film and leads to dryness. Furthermore, extending the use of lenses beyond their prescribed replacement schedule allows protein and lipid deposits to build up on the lens surface. This accumulation reduces clarity and creates an uneven surface that promotes rapid tear evaporation.
Environmental and Lifestyle Factors
External conditions and daily habits influence how quickly the tear film evaporates. Low humidity environments, such as those caused by air conditioning, central heating, or high winds, accelerate the evaporation of the watery component of the tears. When tears evaporate faster than they can be replenished, the contact lens quickly loses hydration and becomes uncomfortable.
Prolonged use of digital screens is a common lifestyle contributor to lens dryness. When focusing intently, the blink rate can decrease significantly, sometimes by as much as two-thirds. Blinking spreads fresh tears across the lens surface, and a reduced rate means the lens remains exposed to the air for longer periods. This insufficient re-moisturization causes the lens to dry out, contributing to a gritty feeling known as digital eye strain.
Underlying Physiological Reasons
Sometimes, dryness stems from an underlying health issue rather than the lens or the environment. A pre-existing condition such as Dry Eye Syndrome (DES) means the eyes do not produce enough tears or the tears produced are of poor quality. Wearing a contact lens on an already compromised ocular surface can intensify symptoms, as the lens further interferes with the limited tear film.
One common cause of poor tear quality is Meibomian Gland Dysfunction (MGD), a chronic condition where the small oil-producing glands in the eyelids become blocked. Since the outermost layer of the tear film is an oily lipid layer, a lack of this oil causes the underlying water layer to evaporate too quickly. Contact lens wear itself can be associated with changes in meibomian gland function, potentially leading to or worsening MGD over time.
Systemic health and medication use can also decrease tear production. Certain oral medications, including antihistamines, decongestants, diuretics, and tricyclic antidepressants, can reduce tear volume. These medications interfere with the body’s natural signaling that prompts tear secretion, leading to reduced moisture. Hormonal changes, such as those associated with birth control or menopause, can also affect tear composition and quantity.
Immediate Relief and Prevention Strategies
For immediate relief, using rewetting drops specifically formulated for contact lenses is the most accessible solution. These drops contain lubricating agents such as carboxymethylcellulose or hyaluronic acid, which help stabilize the tear film and rehydrate the lens surface. It is important to choose formulas labeled for contact lens use, as they avoid ingredients that can damage the lens material. Preservative-free artificial tears are often recommended because preservatives in standard drops can build up in the lens and cause irritation.
Preventative measures involve simple adjustments to lens habits and environment. Taking routine breaks from lens wear, such as switching to glasses for a few hours, allows the eye’s natural tear film to recover stability. For individuals working on digital screens, consciously employing the “20-20-20 rule” (looking away every 20 minutes for 20 seconds at an object 20 feet away) encourages a more regular blink pattern. If dryness persists despite these efforts, or if a lens feels consistently uncomfortable, schedule an appointment with an eye care professional. They can perform a comprehensive dry eye evaluation, confirm the lens fit, and recommend specialized treatments or lens materials.