For contact lenses to truly succeed so that they become the first choice for the correction of refractive error—even over spectacles—a number of lingering issues remain. In a perfectly controlled sterile setting, contact lenses can be adequately comfortable and successful. However, in the real world complete with dust and pollution, and amid populations of patients that vary in ocular surface structure and function; succeeding with contact lenses for the masses has proven to be challenging.
What Constitutes a Suboptimal Environment?
One could argue everyday living conditions are nonideal for the majority of contact lens wearers on this planet. The smoke at the corner bar, reading never-ending e-mails, or even traveling to work in an air-conditioned or heated car can compromise contact lens wear. Think about it: contact lenses are asked to peacefully coexist within the protein and lipid-rich tear film of a patient that lives in a world filled with ubiquitous organisms just waiting to become opportunistic pathogens. Additionally, contact lenses not only increase the evaporation rate of the tear film but can create their own suboptimal environment by adding hypoxic stress with daily and especially overnight use, or through the solutions in which they are bathed.
Fortunately, contact lens associated infection remains rare, and comfort is continually improving. Certainly, industry has given us tools to efficaciously treat just about any refractive error while attempting to combat hypoxia and discomfort. Obviously, they are going in the right direction if already 140 million people wear contact lenses globally. Yet, what do we need to do to retain these wearers and increase the acceptance of contact lenses in the other 450 million people that need and can afford them?
The pages that follow outline tremendous research happening globally. It includes fundamental mechanisms of how contact lenses positively and negatively alter the optical and physiological properties of the eye. The original papers and reviews found herein encompass the quality work happening in our profession and the contact lens research community. As Professor Holden states: “the visual advantages of contact lenses will only be realized if lenses disturb the homeostasis of the eye and its defense systems as little as possible, or if possible enhance them.”