Soft and hard contact lenses
Nowadays contact lenses are presented in a wide variety of brands and designs. The main difference between them is in structure of their material, that can be soft or hard depending on it's optical properties.
Despite the fact that the vast majority of contacts manufactured today are soft, hard lenses are still used. The thing is that both types of contact lenses have their own unique properties and advantages, that are very important for healthy eyesight and comfortable wearing.
The history of contact lenses
First contact lenses were being manufactured of organic glass. This material was very strong and allowed to achieve a sufficient eyesight quality. However, it was too hard and uncomfortable in wearing. Furthermore, organic glass did not pass nutrients contained in oxygen and water. In some cases, the use of these contacts could lead to dangerous eye injuries. People of the past had no choice but to utilize them in spite of any disadvantages. The situation has changed with the advent of hard contact lenses.
Hard contact lenses
Hard contact lenses are rarely prescribed today, but it does not mean that their effectiveness is placed in question. Rigid lenses can perfectly cope with the symptoms of various eye diseases, such as astigmatism, myopia, presbyopia, keratoconus, etc. Their structure has high index of oxygen permeability and contains a sufficient amount of moisture.
These contacts have a number of unique properties that distinguish them from soft lenses:
- Hard lenses can confidently resist to the accumulation of protein and lipid deposits and do not cause allergic reactions;
- Hard lenses are stronger than the soft and they do not lose their shape;
- It is believed that hard lenses provide better eyesight quality than the soft, that can slightly change their shape while blinking;
- In most cases hard lenses are a more advantageous purchase than the soft.
Despite all the advantages hard contact lenses are not as popular among users as the soft, because their use require the period of adaptation. It varies from few days to a couple of months. Moreover, if you will stop wearing hard contacts for some time, you may have difficulties with their repeated use and will have to adapt to them again.
Nevertheless, in certain circumstances the use of rigid lenses is not only possible, but necessary.
Soft contact lenses
Soft lenses were invented at the end of twentieth century and soon became incredibly popular among all users of means of eyesight correction. They were manufactured from innovative materials, that could provide more comfortable and safer wearing than hard lenses. The structure of these lenses has been contstantly improved and perfected, the optical indices have been significantly increased – qualitative eysight has gradually become really affordable for all of those people, who suffer from eye diseases. However, the impossibility of constant wear of these lenses has forced manufacturers to add silicone in the composition of hydrogel contact lenses.
The use of this material allowed to create lenses, that could be used for prolonged and even extended wearing.
In comparison with hard lenses, soft contacts have many remarkable properties:
- No adaptatin period;
- The possibility of extended wear;
- Convenient replacement schedule.
Experts recommend to consult with professional ophthalmologist to select the most suitable contact lenses.