Contact Lens Hygiene: Defence Against the Corneal Ulcer
Contact lenses offer freedom and optical precision, but they are also classified as medical devices for a reason. When mishandled, they can transform from a convenient tool into a significant health risk. The most serious complication we encounter is Microbial Keratitis, which is a serious and potentially blinding infection of the cornea.
At Constantia Eye Clinic, we often treat severe infections that were entirely preventable. This guide outlines the clinical realities of contact lens hygiene and the non-negotiable protocols required to keep your eyes safe.
What is a Corneal Ulcer?
A corneal ulcer is an open sore on the cornea—the clear, front dome of the eye. It is typically caused by a bacterial, fungal or parasitic infection.
Because the cornea is avascular (lacks blood vessels), it has fewer immune defences than other parts of the body. An infection here can progress rapidly, potentially leading to corneal scarring and vision loss which in some cases may need to be treated with a cornea transplant.
Risk Factor #1: Water (Acanthamoeba)
Water is the enemy of contact lenses. Tap water, swimming pools, hot tubs and showers contain a microorganism called Acanthamoeba. While harmless to the digestive tract, it can cause a devastating eye infection called Acanthamoeba Keratitis.
The Protocol:
Never swim in contacts: Unless you are wearing watertight goggles. Prescription swimming goggles are a safer alternative.
No tap water: Never rinse your lenses or your lens case with tap water. The minerals and organisms in the water can bind to the lens surface.
Risk Factor #2: Corneal Hypoxia (Sleeping in Lenses)
Unless you have been prescribed specific "extended wear" (eg silicone hydrogel lenses) by an ophthalmologist, sleeping in your contacts is dangerous. Sleeping in lenses reduces oxygen supply to the cornea (hypoxia). This stress compromises the corneal epithelium (the surface layer), making it easier for bacteria like Pseudomonas aeruginosa to penetrate and infect the eye. Studies indicate that sleeping in lenses increases the risk of infection by 6 to 8 times.
The "Rub and Rinse" Standard
Many patients use "No Rub" solutions, but clinical consensus suggests that mechanical cleaning is superior. The Correct Technique:
Wash hands with soap and dry with a lint-free towel.
Place the lens in your palm and apply solution.
Rub the lens gently with your finger for 10-20 seconds. This friction removes protein deposits and biofilm that bacteria thrive on.
Rinse thoroughly with fresh solution before storing.
The Forgotten Culprit: Your Contact Lens Case
A clean lens in a dirty case is futile. Lens cases are often reservoirs for bacterial biofilm.
Do not "Top Off": Never add fresh solution to old solution. Dump the old fluid, rinse the case with fresh solution (not water) and let it air dry upside down on a clean tissue.
Replace Regularly: You should replace your lens case every 3 months, or immediately after recovering from any eye infection.
When to Stop Immediately
If you experience any of the following, remove your lenses immediately and do not discard them (bring them to your appointment for culturing if necessary):
Redness that does not resolve after lens removal.
Persistent pain or "foreign body" sensation.
Sensitivity to light (photophobia).
Mucous discharge.
Prevention is the Cure Contact lenses should enhance your lifestyle, not threaten your sight. If you have questions about your lens regime or are experiencing discomfort, contact your optometrist for a professional assessment.
