Contact Lenses: What Can Go Wrong?

Dr. Russel Lazarus, September 14, 2020

When it comes to eyewear, contact lenses offer many benefits. But contact lens use can also cause serious complications to your eye health and vision, if you’re not careful.

The cornea, the part of the eye that holds the contact lens in place, is the only part of the body that receives its oxygen directly from the air— as opposed to the rest of the body that receives oxygen from the lungs. When contact lenses are worn, a barrier is erected between the cornea and the oxygen filled environment.

Contact lenses must therefore be designed with the ability to allow oxygen to permeate through the lens, in order to reach the cornea. If a problem arises that prevents this from occurring, serious complications can develop.

  • Serious eye infections affect up to 1 in 500 contact lens users every year.
  • Between 40%-90% of contact lens wearers do not follow instructions on proper care for their contact lenses.

Most conditions that occur from contact lens wear develop as a result of misuse, improper hygiene, or an underlying eye health condition.

The most common conditions include:

Giant papillary conjunctivitis (GPC)

If your eyes feel red and itchy, you may be suffering from an intolerance to your contact lens.

Giant papillary conjunctivitis occurs when round bumps called papillae develop under the eyelid. This is generally caused by an allergic reaction to the contact lens itself.

Treatment generally involves changing the type of lens you wear and the solution you use, as well as eyelid hygiene. Your doctor may recommend taking a break from contact lenses altogether until your symptoms have subsided.

Allergic reaction

If your eyes are red and sore, you may be having an allergic reaction to your contact lens solution. Most people with allergic reactions to their solutions have a sensitivity to the preservatives found in the solution.

Treatment typically involves changing your solution— but always seek your eye doctor’s advice before switching to another brand.

Corneal abrasion

If your contact lens does not fit properly, it will not adhere to the surface of your eye and will move around easily. This can result in a corneal abrasion, or a scratch on the epithelium, the outermost protective layer of the cornea.

A corneal abrasion can also occur if you wear your lenses for too many hours, sleep in your lenses, or a foreign substance gets caught under your lens.

Corneal abrasions can be quite uncomfortable, and may even cause an infection. Treatment of this condition typically involves antibiotics, and sometimes eye patching, if necessary.

Corneal ulcer

A corneal ulcer is a sore that develops on the cornea, generally from a bacterial, viral, or fungal infection.  Contact lens wear increases the risk of corneal ulcers when improper hygiene enables germs to get lodged behind the lens.

This condition can cause corneal scarring and vision loss.

Treatment generally involves discontinuation of contact lens wear for several weeks, or sometimes even permanently, hospitalization until the infection is under control, and corneal transplant surgery to recover normal vision. In very rare cases, patients with severe corneal ulcers lose an eye from the condition.

Corneal de-epithelization

Contact lenses can change the shape of the epithelium, thereby influencing the integrity of the cornea. Your eye doctor will look for signs of this condition during your regular followup visits.

Treatments generally involve taking a break from your lenses until your eye has healed, as well as antibiotics, and a refitting for new contact lenses.

Corneal edema

Corneal edema can result from a sudden or chronic corneal condition in which the cornea is unable to receive enough oxygen. This condition can be caused by an intolerance to specific materials in the lenses, or lenses that don’t fit properly.

Treatment generally involves switching to a contact lens with a higher oxygen permeability that fits appropriately, as well as patient education on reducing lens wearing throughout the day.

Corneal distortion

Wearing contact lenses can cause the shape or curve of your cornea to change. If this occurs, your doctor will first ensure that you have not developed an irregular astigmatism.

Treatments typically involve refitting for new contact lenses and switching to a new brand of lenses that contains different materials.

If you suspect you have an eye condition, contact an eye doctor near you, who can diagnose and treat the condition.

SEE RELATED: Is Sleeping in Contact Lenses Dangerous?

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The cornea is the second most densely-packed innervated organ, after the brain. In many cases, after years of wearing contact lenses, the corneal nerves become desensitized to the contact lenses due to either mechanical trauma or metabolic changes. This can cause problems later on in life.

Sterile infiltrates

This condition occurs as a result of an immune response to your contact lenses and/or bacteria on your contact lenses. This condition can cause a more serious complication called microbial keratitis, and must therefore be closely monitored.

Treatment usually involves prophylactic antibiotics and corticosteroid eye drops.

Microbial keratitis

Microbial keratitis is a type of corneal ulcer that causes an infection of the cornea. This condition is a serious complication of contact lens wear that can cause vision loss. Though rare, it is most often associated with overnight lens wear and extended-wear, as well as poor hygiene or using inappropriate cleansing solutions.

Immediate treatment is required and typically involves oral antibiotics and discontinuing contact lens wear.


This condition occurs when there is a decreased amount of oxygen to the surface of your eye, and causes blood vessels to grow into the cornea.

While this is a rare condition, especially with newer contact lens designs that use oxygenated materials, it is important to follow up with your regular eye exams so your doctor can continue to check for this complication.

Treatment generally involves corticosteroid eye drops.

Reduce your risk of contact lens complications

Reduce your risk of developing a complication from contact lens wear by:

If at any time, you experience eye pain, redness, blurry vision, or discharge from your eyes, promptly remove your lenses and contact your optometrist— if in doubt, take the lenses out.

If your symptoms subside, you may use fresh contact lens solution to clean your lenses, and try to reinsert them. If however your symptoms persist, do not attempt to reinsert your lenses and contact your eye doctor’s office as soon as possible.

LEARN MORE:  Optical and Contact Lenses

Schedule an appointment with an eye doctor to discuss how to achieve the best vision possible.

With proper care and hygiene, your contact lens experience will provide all of the benefits you are searching for.