Targeting contact lens induced dryness and discomfort: what properties will make lenses more comfortable.

There are about 35 million contact lens wearers in North America, and about half of them are symptomatic of dryness and discomfort, more commonly experienced at the end of the lens wearing day. Most of these contact lens wearers do not suffer from true dry eye, which is a pervasive and ubiquitous disease or condition that affects many millions of people in North America. It seems fairly clear that the lens causes the eye to become uncomfortable or "dry," and unless it is effectively remedied, the patient will most likely discontinue lens wear. This review describes the dryness and discomfort effects of contact lenses and how contact lens properties with novel solutions have the potential for eliminating or alleviating these symptoms.