Types and types of contact lenses

There was a time when serious problems of the organs of vision were observed, only among the older generation, now the situation has changed dramatically.

The era of information technology has given us a lot of gadgets and advantages in obtaining the necessary information compared to our grandfathers and grandmothers, but sometimes the benefits of civilization, previously inaccessible, can also hurt.

Fast Internet (videos), a widescreen TV, computer games and remote work - for all this we pay with vision, which can rapidly deteriorate if you do not consult a doctor in time, you can partially lose it and then the intervention of a surgeon will be required.

It is possible to wear glasses, then consult with a specialist ophthalmologist first and wear them to your health. But the article will focus on contact lenses, they have become an integral part of life for many people, do not cause discomfort under the condition of proper operation and are completely invisible, and therefore do not affect the appearance of the person wearing them. There are cosmetic lenses, they change the color of the iris depending on preferences.

Hard lenses

They are prescribed by the attending physician in complicated astigmatism, keratoconus (degenerative inflammation of the eye, occurs when the cornea, which acquires a conical shape, sometimes leads to serious visual complications).

If you blink, this type of lens exerts some pressure on the surface of the cornea, while maintaining the original shape of the lens and thereby increasing the sharpness of the organ of vision. When using them, allergic reactions are rarely manifested, they are more durable, hold better than soft in shape, are easier to clean.

Hard lenses are:

  • As gas-permeable, they consist of compounds of silicone with fluorine. There are disadvantages - this is the active absorption of fats, which are found in creams and cosmetics;
  • So gas-tight, used earlier, are now less common.

Soft lenses

They are prescribed by the attending physician to normalize vision when the patient reveals myopia, astigmatism or hyperopia. They are held by the capillary effect.

Lenses are selected at will, and can change the color of the iris. They are more comfortable to wear, allow air and moisture to pass through, and there is no discomfort on the retina. These lenses come in different hydrophilicities:

  • 50% and more - high;
  • 50% or less - low degree of hydrophilicity.

For reference: There is information - according to statistics, in the world about 10% of people wear hard lenses, while others prefer soft ones.

Replacing lenses with new ones - soft and hard

  • For everyday replacement - suitable for people who value their time and care about their health;
  • For planned and frequent replacements - it is recommended to replace them with new ones in a week or two, depending on the recommendations of an ophthalmologist specialist;
  • For a scheduled replacement - should occur after one or six months. They are divided into monthly, quarterly and semi-annual.

Planned are resistant to the deposition of protein and protein, which complicates the spread of microorganisms, they are recommended to be worn for up to fifteen hours a day.

Traditional soft lenses should be used no more than a year, and accordingly rigid, which are more durable for several years. Hard stand out against the background of others, low air permeability and low moisture content, sometimes the above parameters can lead to discomfort during prolonged wear.

Use up to 10 hours during the day. When applying, in order not to infect the eyes, you need to use a cleaning solution that your doctor can advise, with enzyme tablets, but best of all, just buy saline in a pharmacy and use it to clean your lenses. Do not forget to wash your hands with soap that does not contain dyes and essential oils.

Everyone should know this: no matter how much you wear these lenses, at least a day, month or year, at the end of the planned replacement period, can last from one day to a whole year, the lens must be purchased again, and the old one disposed of.

Contact Lens Wear Mode

  • (FW) Flexible mode, do not remove one or two days, as the lens user is more convenient;
  • (DW) Day mode, night will have to be removed;
  • (EW) When prolonged, you have to live with them for seven days;
  • (CW) A continuous, full-month lens will protect their wearer's vision. It is gas tight and silicone - hydrogel.

Types of Lens Design

  • Spherical shape, used to correct vision problems, like myopia and farsightedness;
  • Aspherical shape, with vision problems that are listed in the paragraph above;
  • Toric form, necessary for astigmatism;
  • Multifocal form used to correct senile hyperopia.

Prescribing contact lenses

  • Optical - used to correct visual defects (presbyopia, myopia, astigmatism and hyperopia);
  • Designed for sports, makes colors more contrast, yellow is used for games such as tennis;
  • Cosmetic lenses - help to hide newly acquired or congenital visual defects of the visual organ (clouding of the cornea or iris colobus);
  • Decorative lenses - change the natural color of the iris, they are tinted and known as Carnival or "Crazy" - the latter is applied to a picture, or various color effects. The peak of popularity comes on holidays - New Year, Halloween and on various thematic events. But it is rather a fashion accessory, and not a means for correcting the visual organ;
  • Therapeutic lenses - used because of the high hydrophilicity as a bandage and for better absorption of various drugs in the tissues of the visual organ.

The degree of transparency of contact lenses

Lenses depend on their purpose and are colored or transparent, which do not stain the iris. Colored lenses are released to facilitate their detection in a disinfectant solution where they can be stored.

Painted, unlike cosmetic ones, do not change the natural color of the eyes and do not give it different shades.

Special healing lenses

The use of scleral lenses - in situations where the usual can not be used or it can be dangerous for the patient, for example: modification of the cornea, postoperative restoration of corneal scars, severe cases of "dry eye" and complications of keratoconus. These lenses are larger than usual, they completely cover the cornea and rest on the sclera. They are individually made and selected for each patient.

These lenses come in different diameters:

  • Scleral is 18.1 - 24.0 mm;
  • Corneoscleral - this is 12.9 - 13.5 mm;
  • Mini scleral is 15.0 - 18.0 mm;
  • Semi-scleral - it is 13.6 - 14.9 mm.

Orthokeratological lens

For a while they are able to correct various visual defects, but the high price, as well as the difficulties in individual selection, they are rarely used.

When donning at night, the thickness of the cornea increases, and their shape changes, which affects the optical power of vision. The effect usually lasts several days. They are recommended to be worn by athletes and people who, due to their specialty (work in dusty and poorly ventilated rooms), cannot afford to change lenses on their own in a timely manner.

Hybrid contact lenses

It is best used for individual intolerance of a rigid type of lens by the patient’s organs of vision, this solution provides increased visual acuity as in the rigid, with the comfort and advantages of soft type lenses.

The center of the lens is made in a spherical shape and is located above the cornea, it is rigid, and the lens itself rests on edges that are soft and do not cause discomfort to the patient.

Watch the video: Types of Contact Lenses (March 2024).

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