The transparent, dome-shaped tissue at the very front of the eye is the cornea, which acts as the window through which light enters and a powerful protective barrier. This highly sensitive structure is easily disrupted, and any injury to its surface can be intensely painful and potentially compromise vision. For contact lens users, the concern is valid: can a device designed to sit directly on this delicate surface cause physical injury? The answer is yes; improper lens practices or the lens itself can directly lead to a scratch on the eye’s surface, known as a corneal abrasion.
What Exactly Is a Corneal Abrasion?
A corneal abrasion is a scratch or scrape on the cornea, specifically damaging the outermost layer called the epithelium. This layer functions as the eye’s primary defense, shielding internal structures from foreign particles and infectious agents. The injury is categorized as a traumatic wound and is one of the most common types of eye trauma.
The cornea possesses one of the highest concentrations of nerve endings in the body, explaining why even a minuscule scratch causes severe, immediate pain. When epithelial cells are scraped away, the underlying nerve fibers are exposed, leading to intense discomfort with every blink. Although the injury is typically superficial, it leaves the eye temporarily vulnerable to infection until the epithelium rapidly heals, often within 24 to 48 hours for minor abrasions.
Specific Ways Contact Lenses Cause Damage
The intimate relationship between a contact lens and the corneal surface creates several opportunities for mechanical injury. One frequent cause of abrasion is a foreign body, such as dust, sand, or an eyelash, trapped between the lens and the cornea. The lens then acts as a grinding mechanism, pressing the particle against the epithelium with every movement and blink.
Improper handling during insertion or removal is another common mechanism for physical damage. If a wearer roughly pokes the eye, drags the lens across the corneal surface, or uses a fingernail to remove a tightly adhered lens, the mechanical force can easily shear off epithelial cells. Furthermore, a chipped, torn, or rough-edged lens can cause constant, repetitive friction against the eye, leading to a break in the protective surface over time.
Over-wearing contact lenses, particularly sleeping in lenses not approved for extended wear, predisposes the eye to injury by compromising the tissue. Prolonged lens use restricts the cornea’s access to oxygen (hypoxia), which weakens the epithelial cells and makes them more fragile. A dry or weakened cornea is far more susceptible to tearing or abrasion upon lens removal than a fully oxygenated, lubricated surface.
Recognizing Symptoms, Treatment, and Prevention
Symptoms of a corneal abrasion are generally immediate and distinct, signaling damage to the protective surface. Patients typically experience sudden, sharp eye pain, a pronounced feeling that a foreign object is stuck in the eye, and excessive tearing. The eye will often appear noticeably red, and sensitivity to light (photophobia) is a common reaction.
If an abrasion is suspected, immediately remove the contact lens and refrain from rubbing the eye, which can worsen the scratch. The eye may be gently rinsed with a sterile saline solution or clean water to flush out debris. Prompt consultation with an eye care professional is necessary, as breaking the epithelial barrier creates a high risk for infection. Treatment usually involves prescription antibiotic drops or ointment to prevent bacterial infection while the eye heals, and sometimes a non-steroidal anti-inflammatory drop is prescribed to manage pain.
Preventing a corneal abrasion largely centers on meticulous lens hygiene and adherence to the prescribed wearing schedule. Following these practices minimizes the risk of mechanical injury and infection.
Prevention Measures
- Always wash hands thoroughly before touching the lenses.
- Use only fresh, sterile solution for cleaning and storage.
- Never wear lenses longer than recommended by the manufacturer or your eye doctor, and avoid sleeping in lenses unless explicitly approved.
- Ensure the lenses are properly fitted by an eye care professional, as an ill-fitting lens can cause chronic friction against the cornea.