[Contact lenses. 1: Contact lens associated complications]

The contactology as frontier between ophthalmology and eye optics requires special attention by part of ophthalmologists. Contact lenses influence the anatomy, the physiology and the immunological responses of the external eye. The corneal metabolic disorders of contact lens wearers are among others, the result of a diminished oxygen supply to the cornea. These disorders are influenced by contact lens deposits, tear film dysfunction and intrinsical characteristics of contact lenses. Sensibilisation and allergic reactions are result of the wearing of contact lenses. Even toxic reactions, as a result of the disinfection systems used, may be observed Ophthalmologists must be able to recognize the contact lens induced diseases and to advice their patients properly. Therefore, regular ophthalmological control examinations are indispensable.