[Contact lenses--medical indications and problems]

Today, hard and soft contact lenses are useful visual aids. In common with any other effective medication, however, they can also produce side effects. They are medically indicated whenever spectacles fail to optimally compensate poor vision. They are not easy to customize, and wearers must be examined by the ophthalmologist more frequently than wearers of eye glasses. Complications are more common with contact lenses than with other visual aids. Nevertheless, modern lens systems do provide optimal correction of impaired sight in any age group. The present paper offers an overview of the limitations and possibilities of treatment with contact lenses, and discusses the medical indications.