How should eyeglass lenses be fitted?

How to choose glasses – basic parameters

There are many factors to consider when choosing prescription glasses – some of them can be read about, for example, at https://www.wokularach.pl/jakie-szkla-do-okularow-wybrac. The optical power of an eyeglass lens is expressed in diopters. Diopters can have positive or negative values, indicating the converging or diverging power of the lens. Determining the optical power of glasses makes it possible to effectively correct various vision defects. The general rule is that hyperopia is corrected with converging lenses, that is, glasses with positive optical power. Myopia, in turn, requires “minus” lenses, or diverging lenses with negative diopters. Presbyopia is usually corrected with positive diopters, while in the case of astigmatism, both the diopter value and the astigmatism axis are important.

There are many lens parameters that affect visual comfort and determine their optical properties. When glasses are made, parameters such as pupillary distance (PD) and fitting height are determined. What do these parameters mean? Pupillary distance is the distance from the center of the pupil to the bridge of the nose, while fitting height depends on the type of frame and is measured where the center of the pupil is located in the glasses. Another important measurement is vertex distance, meaning the distance between the apex of the cornea and the surface of the eyeglass lens.

Which eyeglass lenses will be the best?

As the name suggests, eyeglass lenses are associated with glass. Today, however, most eyeglass lenses are not mineral lenses made of glass, but plastic lenses. Glass lenses have excellent optical properties, while plastic lenses are lighter, more durable and also very convenient to use.

Taking into account the type of vision defect that requires correction, the following types of eyeglass lenses can be distinguished:

  • single-vision lenses, which are ideal for reading or distance vision
  • bifocal lenses, divided into two vision zones – for distance and near vision
  • progressive lenses, with a gradual change in focal length and enabling comfortable vision at every distance
  • aspheric lenses are not made from a section of a sphere, which allows them to reduce image distortions caused by the curvature of the lens; this solution works well for people with a stronger vision defect, above 4 diopters, who care about the aesthetic appearance of the lenses and their comfortable use; such lenses are thinner than their spherical counterparts and less convex.

Coatings for eyeglass lenses – which are essential?

The surface of eyeglass lenses can be enhanced with suitable coatings that improve visual comfort while also providing additional protection for the eyes. One of the most practical coatings of this kind, ideal for people who spend a long time in front of a computer monitor, is a Blue coating. It filters blue light emitted by LCD devices. This helps protect the eyes from becoming tired or irritated too quickly, as well as from the premature development of macular degeneration. A photochromic coating, which provides protection against UV radiation, is another useful solution. This coating has unique properties – indoors, the eyeglass lenses are completely transparent, while under the influence of sunlight they darken, blocking UV radiation. In this way, by wearing one pair of glasses, we can both correct a vision defect and protect against UV light – without having to use two pairs of glasses.

A polarizing coating prevents glare, which is why it is ideal for drivers. This coating works well in conditions of strong sunlight, while skiing or spending time near water. The coating provides impeccable visual sharpness and image saturation. The online store wokularach.pl offers a huge selection of glasses, including options enhanced with suitable coatings. The store offers glasses at very attractive prices, enabling customers to purchase both high-quality lenses and eyeglass frames.