Creating colored contact lenses or their cleaning solutions at home introduces significant risks to ocular health. This do-it-yourself practice bypasses established safety protocols designed to protect the delicate tissues of the eye. The resulting homemade devices and liquids are inherently flawed, posing a threat of infection, chemical burn, and permanent vision loss.
The Dangers of DIY Contact Lens Materials
A homemade contact lens lacks the precise engineering required for safe corneal interaction. Commercial lenses are made from medical-grade polymers like silicone hydrogel, designed for high oxygen permeability to prevent hypoxia. Non-medical plastics used in DIY projects create a barrier that starves the avascular cornea of oxygen, leading to corneal edema or swelling.
The physical fit is also critical, as an improperly sized lens will not move correctly on the eye. A tight fit can lead to corneal abrasion, a painful scratch on the surface of the eye, which increases the risk of serious infection. Household dyes used to color the lens are not chemically inert and can leach toxic substances, such as chlorine, directly onto the ocular surface, causing irritation. Furthermore, the non-sterile environment of creation means pathogens can become embedded directly into the lens material.
Chemical and Sterility Hazards of Homemade Saline
The liquid used to rinse and store contact lenses must be a sterile, buffered solution with specific osmotic properties. Homemade saline solutions fail to meet this standard, often leading to a chemical imbalance or biological contamination. An ideal commercial solution is isotonic, containing approximately 0.9% sodium chloride, which matches the osmotic pressure of the eye’s natural tears.
A solution that is not isotonic, such as one made with an incorrect salt-to-water ratio, can be hypotonic, causing corneal cells to absorb water and swell, or hypertonic, causing them to shrink. Tap water, even when boiled, is not sterile and often harbors Acanthamoeba, a free-living amoeba. This parasite is a major cause of Acanthamoeba keratitis, a difficult-to-treat eye infection. Homemade solutions also lack the antimicrobial agents necessary to disinfect the lens surface between uses, allowing bacteria and fungi to proliferate.
Immediate and Long-Term Ocular Health Consequences
The use of homemade lenses and solutions raises the risk of severe ocular infections, including bacterial keratitis or fungal infections. When the cornea is damaged by a poorly fitting lens or chemically irritated by toxic dyes, it becomes vulnerable to these pathogens. These infections can rapidly progress to form a corneal ulcer, an open sore on the eye’s surface.
If the infection is caused by the Acanthamoeba parasite, the resulting keratitis can cause severe pain and is often resistant to conventional treatments. Chronic oxygen deprivation (hypoxia) from a non-permeable lens can lead to the growth of new, abnormal blood vessels into the clear cornea, a condition called neovascularization. Scarring left behind by corneal ulcers or damage from infection can cause permanent loss of visual acuity. In the most severe cases, a corneal transplant may be required to restore vision.
Why Regulatory Oversight is Essential for Eye Safety
The safety of commercially available contact lenses is mandated by strict regulatory oversight. In the United States, the U.S. Food and Drug Administration (FDA) classifies all contact lenses as medical devices, whether corrective or cosmetic. This classification requires manufacturers to prove that the lenses meet specific standards for material purity, oxygen transmission, and sterility.
Regulatory review ensures that the lens design is standardized to a precise range of sizes for proper fit on the eye. Even cosmetic colored lenses require a professional eye examination and a valid prescription from an eye care practitioner. This process confirms the lens is custom-fitted to the wearer’s eye curve and size, which is a safeguard against corneal damage. Consumers must only purchase lenses and solutions from approved vendors who adhere to these established medical device standards.