Contact lensees are usually divided into two types. One is the hydrophobic hard contact lens made mainly from polymethylmethacrylate (PMMA), and the other is the hydrophilic soft contact lens made from polyhydroxyethylmethacrylate (PHEMA) or polyvinylpyrrolidone (PVP). Recently oxygen permeable hard contact lenses made from silicone have been widly used.
Relationships between surface science and contact lenses are as follows;
1. deposits or coatings on the contact lens surface
2. wettability of the contact lens surface
3. surface hardness of the contact lens
4. tear evaporation from the contact lens surface
5. oxygen permeability
For soft contact lenses, it is particularly important to solve the problems described in 1, 4, and 5 above. For hard contact lenses, the problems described in 2 and 5 are important and likewise for oxygen permeable hard contact lenses, the numbers 1, 2, 3, and 5 are important.
If it is possible to solve some of these problems by the development of the surface science of the contact lenses, the contact lenses will be more comfortably availble to the patinents.