Contact lenses offer a convenient way to correct vision, but wearing them for too long can lead to discomfort and eye redness. This reaction signals that the delicate surface of the eye, the cornea, is under stress and requires immediate attention. Understanding the reasons behind this redness and knowing the proper steps to take are necessary for protecting long-term vision health.
Why Prolonged Wear Irritates the Cornea
The primary reason for redness after extended contact lens use is corneal hypoxia—a lack of sufficient oxygen reaching the cornea. The cornea must draw its oxygen directly from the surrounding air, absorbed through the tear film. A contact lens acts as a physical barrier, significantly reducing the oxygen that reaches the underlying corneal cells. When these cells are starved of oxygen, they become stressed and swell.
Oxygen deprivation triggers the dilation of blood vessels around the edge of the cornea, called the limbus, as the body attempts to increase blood flow. This vessel swelling produces the distinctive red or “bloodshot” look in the white of the eye. Chronic hypoxia can lead to abnormal blood vessels growing into the cornea, a process called neovascularization, which can permanently affect vision.
The prolonged presence of a lens also disrupts the natural tear film. The lens absorbs some tear film and accelerates tear evaporation, leading to dryness and friction against the corneal surface. Proteins, lipids, and environmental debris collect on the lens surface over hours of wear, creating a toxic layer that mechanically irritates the eye with every blink. This accumulation of deposits also harbors microorganisms, increasing the risk of infection.
Immediate Self-Care Actions
The moment you notice redness, irritation, or a foreign body sensation, remove the contact lenses immediately. Discard daily disposables; reusable lenses should be thoroughly cleaned and stored in fresh solution. Do not attempt to re-insert the lenses, even if they feel slightly better after a short break.
After lens removal, the eyes need rest and lubrication to promote corneal healing. Use preservative-free artificial tears or lubricating eye drops frequently to wash away irritants and restore moisture. Avoid over-the-counter “redness-relieving” drops, as these products contain vasoconstrictors that temporarily shrink blood vessels, masking the underlying problem without addressing the irritation or hypoxia. Avoid activities that cause strain, such as prolonged screen time, and forgo eye makeup application until the redness has completely disappeared.
If the eye feels scratchy or the redness is persistent, a cool compress gently applied to the closed eyelids can help soothe inflammation and reduce swelling. If symptoms do not begin to improve within a few hours of lens removal and lubrication, or if they worsen, a more serious issue may be developing that requires professional evaluation.
Symptoms That Require Emergency Care
While mild redness often resolves with lens removal and rest, certain symptoms warn of serious eye conditions, such as infectious keratitis or a corneal ulcer. Severe, sudden, or rapidly worsening pain that persists after the lens is removed is a primary sign that the cornea may be damaged or infected. This level of pain is not typical of simple dryness.
Any significant change in vision, including new blurriness, haziness, or a decrease in acuity, demands immediate medical attention. Photophobia, an extreme sensitivity to light, also requires urgent care. If you find yourself needing to keep the eye closed or shielded from light, contact an eye care professional without delay.
Signs of Infection or Serious Damage
If you experience any of the following, seek immediate professional care:
- The presence of discharge, particularly if it is thick, yellow, or green, or if the eye feels sticky upon waking.
- A foreign body sensation that does not resolve after lens removal and flushing with saline, which may indicate a corneal abrasion or ulcer.
- Redness concentrated in a specific area or forming a dense ring directly around the edge of the iris, suggesting localized inflammation or infection.
These symptoms require prompt diagnosis and prescription medication from an eye doctor to prevent permanent scarring or vision loss.
Essential Rules for Contact Lens Safety
Adherence to prescribed wearing schedules is essential for contact lens safety. Never wear lenses longer than recommended, and avoid sleeping in them unless they are specifically approved for extended overnight wear. Sleeping in lenses increases the risk of serious infection by up to tenfold.
Proper hygiene is paramount, beginning with washing hands and drying them with a lint-free towel before handling the lenses. Lenses must be cleaned and disinfected exactly as instructed, which often involves rubbing them with solution rather than simply soaking. Never use water, tap water, or saliva to clean or store lenses, as these contain microorganisms that can cause severe infections.
Follow the replacement schedule for both your lenses and your lens case precisely. Lenses must be replaced on time, whether they are daily, biweekly, or monthly, because protein deposits and contaminants build up over time, even with proper cleaning. The lens storage case should be replaced at least every three months, as the plastic can harbor biofilm and bacteria. Every contact lens wearer must maintain an up-to-date pair of prescription eyeglasses as a non-negotiable backup. These glasses allow you to rest your eyes immediately upon irritation or infection.