Contact lenses offer a convenient alternative to eyeglasses, providing clear vision and freedom for various activities. However, these medical devices require diligent care and adherence to recommended wearing schedules. Misusing contact lenses, particularly by wearing them for extended periods, can lead to a range of ocular complications, from minor irritation to severe, vision-threatening conditions. Understanding these potential consequences is crucial for maintaining optimal eye health.
Immediate Signs of Overwear
When contact lenses are worn beyond their recommended duration, the eyes often signal distress through immediate symptoms. Dryness is common, as lenses absorb the tear film, leaving the eyes feeling parched. This dryness frequently leads to a gritty or foreign body sensation.
Redness of the eyes, sometimes accompanied by irritation or a burning feeling, also serves as an early warning sign. Temporary blurred vision or discomfort can occur, as the lenses may dry out and become misshapen. These discomforts indicate the eyes are under strain and need a break from lens wear.
Serious Health Risks
Prolonged overwearing of contact lenses can lead to more severe and potentially sight-threatening complications. One serious condition is a corneal ulcer, also known as bacterial keratitis, an open sore on the cornea. These ulcers are often caused by bacterial infections, such as Pseudomonas aeruginosa, and can develop rapidly, sometimes causing significant vision impairment within 24 hours if left untreated. Symptoms include severe eye pain, redness, sensitivity to light, blurred vision, discharge, and sometimes a visible white or gray spot on the cornea.
Another risk is corneal neovascularization, the abnormal growth of new blood vessels into the clear cornea. The cornea normally lacks blood vessels to maintain its transparency, and their intrusion can obstruct vision. This condition is triggered by insufficient oxygen reaching the cornea due to prolonged lens wear, especially sleeping in lenses not designed for overnight use. Symptoms include redness around the cornea, pain, light sensitivity, and decreased vision.
Giant Papillary Conjunctivitis (GPC) is an allergic reaction where large bumps, called papillae, form on the inner surface of the upper eyelid. This condition is common among soft contact lens wearers. GPC can cause increased mucus production, itching, eye redness, a feeling of something in the eye, and mild blurring of vision. Untreated GPC can lead to damage to the eyelid and cornea. Other infections, including those caused by fungi or amoebae, are also serious risks associated with contact lens use and can lead to vision loss or even blindness.
Why Overwearing Causes Harm
Overwearing contact lenses harms the eye due to its delicate physiology. A primary factor is oxygen deprivation, or hypoxia, to the cornea. The cornea, the clear front part of the eye, receives its oxygen directly from the air because it lacks blood vessels. Contact lenses act as a barrier, reducing the oxygen flow to the cornea, and prolonged wear can lead to a hypoxic state, causing the cornea to swell.
Contact lenses can trap bacteria and debris against the eye’s surface, creating an environment conducive to microbial growth. This bacterial buildup increases the risk of serious infections. Over time, the material of the contact lens can degrade, leading to changes in its shape or surface properties. This degradation can result in microscopic tears or roughened surfaces, which can then abrade the delicate corneal surface. Finally, contact lenses can impede the natural flushing action of tears, which normally help clear away foreign particles and waste products. Reduced tear exchange allows irritants and microorganisms to accumulate, contributing to discomfort and infection risk.
Protecting Your Eye Health
Adhering to proper contact lens care safeguards eye health. Always follow the wearing schedule prescribed by an eye care professional, whether for daily removal or extended wear limits. It is important to never sleep in lenses unless prescribed for overnight wear, as this increases the risk of complications.
Maintaining hygiene practices is crucial. Always wash hands thoroughly with soap and water and dry them with a lint-free towel before handling lenses. Use only fresh, sterile contact lens solution for cleaning and storing lenses, and never reuse old solution or “top it off.” Replace the lens case regularly, typically every three months, and avoid exposing lenses to water, including tap water, pools, or hot tubs. If persistent discomfort, redness, pain, or changes in vision occur, remove the contact lenses immediately and consult an eye care professional without delay. Having backup glasses is also advisable to allow eyes to rest from contact lens wear when needed.