Soft contact lenses normally consist of hydrogel, less often of silicon. This lens material absorbs tear fluid and therefore requires a sufficient tear production. Proteins and dirt particles can get deposited in the sponge-like structure, which is why soft contact lenses require a special cleaning.
The time required for getting used to wearing them is much shorter than in the case of hart contact lenses due to the much reduced feeling being a foreign body, soft contact lenses are also very well suitable for very sporadic (temporary) wearing.
In contrast to hard contact lenses, with a diameter of around 13mm soft contact lenses are somewhat bigger than hard stable contact lenses (ca. 10 mm). They are, therefore, slightly more difficult to handle and if not cleaned sufficiently more frequently cause infections of the cornea or conjunctiva. Like hard contact lenses, most soft contact lenses must be taken out before going to sleep.
Besides the normal soft contact lenses (yearly lenses), so-called exchange systems are available. They are distinguished by periods of use of various durations (daily, weekly, monthly lenses). The advantage: one always has a fresh contact lens with constant material quality. After the end of the set period for wearing, the contact lens may no longer be used and must be replaced by a new lens (exchange system).
Advantages of soft (flexible) contact lenses:
- Shorter time required for getting used to wearing them
- Better wearing comfort
- Less feeling of being a foreign body
- Sporadic wearing possible
- Good adhesion
Disadvantages of soft (flexible) contact lenses:
- More costly cleaning
- Shorter useful life
- In the event of corneal irregularity less optical quality
- More difficult to manage