Modern room lenses help restore visual acuity and provide comfort. Their types are divided depending on the material of manufacture, the replacement period and other factors. Thanks to such a large classification, everyone can choose for themselves the best option in quality and price. And to make the choice easier, we suggest that you familiarize yourself with what kind of contact lenses (types and types) are. You will also learn how to select them and study the recommendations for care.
Bit of history
Contact lenses, like glasses, are a non-surgical method for correcting vision. For the first time, Leonardo da Vinci spoke about them at the beginning of 1500. After 387 years, the glassblower and Germany Müller made a glass lens that could be placed in the patient’s eye. Since then, several attempts have been made to create not only high-quality, but also comfortable contact lenses.
In 1960, the first soft lenses appeared and ten years later their mass production was established. Over the years, various leading companies have developed new technologies and creations, as well as materials and the appearance of the surface, it has become possible to wear a lens without removing without damage to health and so on.
Today's market offers a lot of lens options designed not only to correct vision, but also to change the natural shade of the cornea. But, despite this, each brand is trying to further expand the lineup for the convenience of its consumers and does not stop developing new types. For example, today the types of contact lenses Akuvyu are:
- for people with myopia or farsightedness - one-day, long-term wear, for sports, reusable, two-week, for correction and shine;
- for people with astigmatism - one-day and two-week.
Types of Contact Lenses
To date, there is a classification according to the following criteria:
- depending on the material of manufacture: soft and hard;
- by replacement period: daily, frequent scheduled (after one to two weeks), planned (after a month, quarter, six months);
- from the mode of wearing: daily, flexible, prolonged and continuous wearing;
- special purposes: scleritic, orthokeratological, hybrid;
- cosmetic: color and tint.
Soft contact lenses
Soft contact lenses are the most common type. They are prescribed to people with farsightedness, myopia, astigmatism and senile hyperopia. They can also be used for medicinal purposes (for example, when there is a need to inject drugs into the eyes or protect them in order to speed up the healing process).
Their advantages:
- wearing comfort;
- the ability to absorb moisture;
- ability to pass air;
- they are not felt on the retina.
Types of soft contact lenses:
- hydrogel - they contain a high percentage of moisture, and the surface is very smooth, elastic and elastic;
- silicone hydrogel - characterized by a high oxygen permeability, and they also hold their shape well.
This type is not used in the presence of defects in the shape of the cornea. Due to their elasticity, the lenses do not have the desired effect. The disadvantage of such lenses is that when dried, they become hard and brittle, so they can only be stored in a special solution. They also require careful handling, because they can easily tear.
Hard lenses
Hard contact lenses are prescribed by ophthalmologists in cases where the patient has a change in the shape of the cornea, which cannot be fixed with a soft look. This may be, for example, astigamtism. The process of adaptation to them takes some time. At the very beginning of wearing, they are felt before our eyes. This is especially felt when blinking. The main feature of hard contact lenses is that they are manufactured in special laboratories according to the individual parameters of the patient, since it is necessary to precisely match the inner surface of the lens to the cornea.
Types of contact lenses for hard type eyes:
- gas-tight - oxygen does not penetrate through them;
- gas permeable.
Advantages of such lenses:
- more durable;
- keep their shape well;
- give a clear and sharp image;
- easier to clean from pollution.
According to statistics, all over the world, only 10% of patients wear hard contact lenses. The remaining 90% use soft ones.
The hard type is prescribed for severe forms of astigmatism and keratoconus. In the process of creating such lenses, more rigid materials are used. At first they are felt before our eyes with each blink, and the process of getting used to takes time. But this type perfectly retains its shape and is durable, and also, as a rule, does not cause allergic reactions, since deposits on hard lenses form more slowly than in the case of soft lenses.
Replacement Date
The contact lens replacement period is the time period specified by the manufacturer in which contact lenses can be used. After it expires, the old pair must be replaced by a new one.
According to the replacement period, the following types of contact lenses for the eyes exist (photo examples above):
- Daily replacement: every day you need to wear a new pair. This type provides maximum comfort, and also guarantees high hygiene of use. The disadvantage is the high cost.
- Often scheduled replacement : the frequency of putting on a new pair is one to two weeks or one month. This type is optimal in terms of price and hygiene. You can wear lenses for several days without removing.
- Planned replacement. They are divided into monthly, quarterly and semi-annual. This is the most economical option. Despite the fact that they are resistant to the formation of protein and protein deposits, the deposition of microorganisms, to achieve a high level of hygiene, it is necessary to use high-quality solutions for their cleaning. Such contact lenses do not provide for continuous wear for more than a day and it is recommended to remove after 15 hours.
All types of contact lenses must be replaced after the specified replacement period. Both their properties and the level of hygiene decrease after a certain time, and this affects not only the image quality, but also the health of the eyes.
By wearing mode
This is not the same as a replacement period. Wear mode implies a maximum period of time during which contact lenses can not be removed. It is due to certain characteristics of the material from which they are made, as well as the replacement period.
The wearing mode may be as follows:
- daytime (DW): lenses worn in the morning and removed at night;
- flexible (FW): allows you to sleep one or two nights in such a pair of lenses;
- prolonged (EW): contact lenses of this type can be worn for up to six days without removing;
- Continuous (CW): The wearing mode without taking off is increased to thirty days.
The last mode of wearing appeared when rigid gas-permeable and silicone-hydrogel materials were used in the process of manufacturing contact lenses. They provide a high level of oxygen permeability.
The prolonged and continuous mode of wearing includes frequent scheduled replacement of contact lenses. Types of planned replacement lenses are characterized by daily and flexible periods.
Cosmetic contact lenses
Cosmetic lenses were originally intended to correct various congenital or acquired eye defects (for example, clouding of the cornea). Today they are used to change the natural color of the eyes and create an unusual image.
Cosmetic lenses are:
Both that and others are issued both with optical power, and without it.
Colored contact lenses completely change the color of the eyes or enhance the saturation of the natural shade. Their pupil area remains transparent to maintain image quality. Previously, the range of such products was limited only to the color palette.
Types of colored contact lenses:
- Color: a densely colored lens with an imitation of a complex pattern of the iris of the eye. They allow you to turn saturated brown eyes into honey tea or soft violet. There are one-day and long-term wear. The color palette is very diverse and has a huge number of all kinds of shades.
- Crazy (carnival) lenses: differ in a variety of color patterns and effects applied to the iris. They are very popular during holidays such as New Year and Halloween, as well as at various theme parties and comic cones (a festival dedicated to comic book superheroes). They are also popular with theater artists. The choice of such lenses is striking in its diversity. You can find emoticons, a chessboard, neon eyes, or turn into a cat, a vampire, a witch, and so on.
Tinted contact lenses differ from color in the degree of color saturation. They do not completely change the color of the iris, but can only enhance the natural shade of the eyes. To such contact lenses, the pupil area is also colored. But this does not affect vision. After all, the degree of coloring is so weak that a natural pattern of the iris is visible through the lens.
Specialty Contact Lenses
Scleral lenses are used in rare cases when the patient has an irregular shape of the cornea, cider of the “dry eye”, keratoplasty has been previously transferred and so on. In this case, under the lens there is a space that is filled with tear fluid. This type is made individually for each and is divided into root-scleral, semi-scleral, mini-scleral and scleral.
Orthokeratological contact lenses are distinguished by high cost, complexity of selection and its complexity, as well as the need for a keratotopograph (special equipment). This type is intended to correct myopia of up to six diopters, as well as myopic astigmatism up to 1.75 diopters. Suitable for athletes, people who work in dusty rooms and so on.
Hybrid contact lenses are used in cases where the patient needs a hard type, but there is an individual intolerance. Currently, they are also prescribed to correct astigmatism of high degree and keratoconus.
How to make a choice?
Modern technology allows you to create new types of contact lenses. Which is best advised only by an ophthalmologist. It carries out the necessary procedures and determines the parameters that affect the choice of lenses. The doctor writes you a prescription and recommends several types of contact lenses based on your lifestyle and needs.
During the examination, parameters such as visual acuity with each eye, refraction, the state of accommodation and fundus, the thickness and shape of the cornea, and so on, are determined. Not only the quality of the patient’s vision, but also how comfortable it will be for you to use certain types of contact lenses depends on the accuracy of all the data. For ophthalmoscopy (fundus examination) and measuring the radius of curvature, for example, it is important to have the necessary equipment that allows you to conduct a full study. So in order to use contact lenses was comfortable and they did not cause any irritation, visiting a doctor is a prerequisite.
After the examination, the doctor gives recommendations on the choice depending on the profession of the patient, his hobbies and so on. For example, drivers of vehicles use lenses that can not be removed at night and do not require special care. And people who spend a lot of time in front of a computer monitor need those who have increased gas permeability. Such a lens does not dry out the mucous membrane of the eye and prevents possible irritations.
In conclusion, the doctor offers some kind of contact lenses, depending on all of the above parameters and the financial capabilities of the patient, and also teaches the use and gives recommendations for caring for them.
With the right selection of contact lenses, you need to visit a doctor from time to time. Perhaps some of your options have changed and you will need to change the recipe.
Recommendations for care and use
- Before putting on and removing lenses, wash your hands with soap and water.
- Makeup is applied after the lenses are worn.
- Always use a new solution and keep track of its expiration date.
- The container is replaced every three months.
- Each time you remove contact lenses, they must be carefully cleaned under running water or a solution.
- Use special tweezers. It does not damage the lens.
- For various damage to contact lenses, they need to be replaced.
- You can not store two lenses in one cell of the container.
- It is not recommended to swim in the lenses, as they can be washed off by water.
- The solution is poured into a container, and then lenses are placed in it.
- Contact lenses left without a solution quickly dry and deform.
If you adhere to the above and other recommendations prescribed by your attending ophthalmologist, the use of contact lenses in everyday life will be comfortable and not harmful.