A contact lens is a thin lens placed directly on the surface of the eye, primarily the cornea with the aim of correcting refractory anomalies, treating eye disorders, removing cosmetic defects, and changing eye color. Depending on the type of material, we divide them into two large groups - soft and hard. Depending on the anticipated period of use, we differentiate daily, two-week, monthly, quarterly, and yearly. Some of the most important indications are: keratoconus anterior, irregular astigmatism, anisometropium, afacita and pseudophysium, amethropia, cases in which glasses do not achieve satisfactory visual acuity, presbyopia, albinism and changes in iris. Choosing the type of contact lens depends mostly on the indication. Prior to any prescribing of contact lenses, a detailed ophthalmic examination, refractometry and keratometry should be performed. By developing contact lenses, the number of complications is reduced but still present. Today, the most common complications are hypoxic-hypercapneal and infectious one. Therapy is mostly symptomatic, except for serious infectious complications when we use antibiotic locally. It is important to emphasize the importance of proper cleaning and maintenance of the lens, which in fact prevents a large number of complications.