Lenses for eyes by curvature, according to options — normal, colored, decorative
Lens selection is a very important process which should be addressed by a professional. Among the wide variety of products offered to us today by the pharmaceutical industry, it is easy to get lost. Contact optical devices are colored and transparent, of different diameters, thicknesses and made of different material.
That’s not all the criteria according to which you must make a choice. The selection comes after a thorough examination by an ophthalmologist, and this is because the products have some contraindications.
Contact lenses: selection of the parameters of the product
The main parameters of choice:
- the radius of curvature;
- power optics.
The diameter of soft options is from 13 to 15 mm. Often patients use products with the size from 13.8 to 14.5 mm. the Choice is made based on the measurement of the cornea, which in many cases is the same in both eyes.
Such criteria as the radius of curvature affects the fit on the cornea. The radius of curvature is called the deviation of the inner wall of the product, which has the shape of a sphere. It is important to ascertain, otherwise a bad fit will cause complications.
Lenses curvature depends on the shape of the cornea. The standard value of this index is in the range of 8.1 – 8.9 mm. With the help of special equipment, the doctor determines the curvature of the cornea of the patient and selects the contact correction means.
Another important criterion is the optical power. It is expressed in numbers which can have positive or negative values. The ophthalmologist must calculate the degree of deterioration of your vision and thus, to choose the required power of the device. This is done by oversight of the eyes of different options as long as the patient will not normally perceive the image.
All colored contact tools can be divided into several types:
- translucent or tint;
- opaque or decorative.
The first group is the translucent options also called tinted. They are poorly painted in different colors, and can only increase your natural shade of the iris. The effect is achieved through the purchase of products that are similar in color to your natural shade. So can blue eyes to make blue, green – turquoise, brown and blue.
As for the second group, it is opaque glass. They have intense color and painted over completely. They can be drawn pictures of the iris, unusual images, color tints and many more. They can dramatically change not only the color of the visual organs, but also form pupil.
These decorative lenses are very popular lately. They are not only used by actors and theatre workers, but also applied in everyday life. Many manufacturers produce such goods, covering a large sphere of possibilities. Each model of the products can cover from 5 to 15 colour variations. This allows the buyer to make their choice.
Lenses eye occurs on the basis of these criteria. Coloring options are more light-eyed people, use decorative optical products absolutely all in the absence of contraindications.
Important! When choosing color lenses, it is necessary to pay attention to the quality of visual function. If the patient requires vision correction, the lens should have a diopter, so that a person could normally see. In that case, if the vision is normal, it is possible to use conventional products that are not in any way affect the vision, but only have an aesthetic function.
Choose those or other means of contact correction for a person can only ophthalmologist. It is important before it to be examined to check your vision and take all the necessary measurements. On the basis of individual indicators and make a selection. If you ignore the rules and use the standard lenses, they may not be appropriate for the optical power or planting that will eventually lead to a further deterioration of visual function and feelings of discomfort in the eyes.