BAK, standing for Benzalkonium chloride, is a widely used eye drop preservative that can have detrimental effects on the ocular surface. Most prescription and over-the-counter eye drops contain BAK, known to worsen dry eye symptoms in multiple ways. Consumers often use BAK-containing eye drops without realizing the potential long-term risks.

It is crucial to be aware of the preservatives in your eye drops and to discuss alternatives with your eye care provider. Prescription eye drops for conditions like glaucoma may contain varying percentages of BAK, so it is essential to use this information responsibly and not stop medication without consulting a healthcare professional. Some OTC eye drops also contain BAK, but the concentrations are not always disclosed.

By understanding the risks associated with BAK, consumers can make informed decisions about their eye care and work towards minimizing preventable dry eye caused by preservatives