Special malfunctions of vision can be corrected better. Typical spectacles' problems are avoided, such as inconvenient pressure, sliding off the nose, fog on the glass. In addition, the invisible help of vision offers cosmetic advantages. The adjustment of contact lenses demands time, in order to provide individual care. Deliberate care with special fluids and all the handling has to be trained and consequently be carried out.
Lenses have to be changed regularly.
Incorrect handling of the lenses or insufficient hygiene can lead to infections and haze of the cornea, which reduces the power of seeing.