The Complete Handbook of Contact Lens Solution

Chapter 1: Understanding Contact Lens Solution

Contact lens solution is a medical device, not an accessory. It is regulated by national health authorities and is designed to perform specific physical and chemical tasks on a hydrophobic polymer surface that is worn directly on the cornea. To understand what it does, you have to understand what it is up against: a lens, fresh from your eye, is covered in a film of mixed proteins (lysozyme, albumin, mucin), lipids from the meibomian glands, salts from your tears, and the cellular debris of your own corneal epithelium. That is not a cleaning problem; it is a biochemical problem. The solution in the bottle is the only thing standing between that fouled lens and a comfortable, healthy fit the next morning.

At the most basic level, contact lens solution does four distinct jobs: disinfect, clean, condition, and store. One product, typically a multipurpose solution, must do all four. Understanding how a single liquid can accomplish these tasks, and how the formulation changes when each job takes priority, is the core of this book. It is a chemistry and engineering problem as much as a medical one.

The Composition of a Multipurpose Solution

Open a standard, multipurpose contact lens solution bottle and read the inactive ingredients. You will see water, sodium chloride, a buffer such as borate or phosphate, a surfactant like poloxamer or Tetronic 1304, and a preservative. The active ingredient column will list a biocide. That is it. There are no enzymes in