Before entering fully into the meaning of the term monofocal, we are going to tell you what its etymological origin is. In this case, we can emphasize that it is the result of the sum of two very different words:
-Monkey, first of all, derives from Greek. Exactly from the word “monos”, which can be translated as “one” or “alone”.
-Focal, secondly, comes from Latin. Specifically, it emanates from “focalis”, which is formed from the union of two lexical components: the noun “focus”, which is synonymous with “home”, and the suffix “-al”, which is used to indicate “ relative to”.
The notion of monofocal is used in the field of optics . It is an adjective that is used to describe lenses that have the same prescription on their entire surface .
A monofocal lens allows the correction of any type of refractive error, such as presbyopia , astigmatism , hyperopia or myopia . As they have a single graduation, they are used for a single specific purpose: for driving (they improve distance vision), for reading (they improve close-up vision), etc. If the person has more than one problem, they will need another type of lenses.
A visual dysfunction occurs when an eye defect makes it difficult for light to reach the retina correctly, which results in disorders of focus and, therefore, visual acuity. The lenses allow this defect to be reversed or minimized: in the case of monofocals, having the same prescription throughout its entire length.
Depending on the refractive error to be treated, the monofocal lens has different characteristics. For myopia , for example, concave and divergent monofocal lenses are used, which are thinner in the central part and thicker in the edge areas. In the case of hyperopia , however, monofocal lenses are convex and converging, thinner at the edges and thicker in the center.
It is important to mention that the adjective monofocal also appears in expressions such as monofocal lenses , monofocal glasses or monofocal glasses . The concept always refers to a single graduation in the element in question.
Compared to monofocal lenses, we come across multifocal lenses, which can be of two fundamental types:
-Bifocal lenses, which, as their name indicates, are those that have two different focal lengths. Thus, the lower part makes it easier to see the elements that are closest and the upper part allows you to correctly see the objects that are further away.
-Progressive lenses, which are those that have an appearance in which it is not perceived that there are two focus areas, but that it does have several. Specifically, the lower area is used to see up close, the intermediate area to see objects that are at a medium distance and the upper area to appreciate elements that are further away. Hence, the person who wears them must learn to look properly through the part of the lens that is needed at all times.