WHAT IS A PROGRESSIVE LENS?
A progressive lens is used to correct vision defects, such as presbyopia or eyestrain, which is characterized by a decreased ability to see close objects clearly. Although, for this reason, it has been considered that progressive glasses were indicated for the elderly; Nowadays, with the massive use of screens (e.g. computer) this has changed, and progressive glasses are ideal for those who have refraction problems in their eyes, regardless of their age.
Before, instead of progressive lenses, bifocals were used to be in front of the computer, although with progressive lenses some of the problems of using computers and other screens are solved, since the transitions are made in a more natural way, without that there are areas of vision that "cut" more abruptly, as is the case with bifocals. Progressive lenses are divided into three zones: the upper part, for the correction of vision at far distances; the lower part, which corrects vision at short distances, and a corridor for intermediate distances, which is the area that ensures that there is no sharp cut between far and near, but rather that this jump is progressive.
When you are working with a computer, the distance between our eyes and the screen is usually about 40 centimeters, that is, it is quite close. If we wear bifocals, we are forced to tilt our heads up at an awkward angle to properly focus on the screen; that is, we do not correct presbyopia in the lower third, something that does happen with progressive lenses: progressive glasses, by having this gradual graduation, improve vision.
WHY ARE PROGRESSIVE LENSES MORE EXPENSIVE THAN SIMPLE OR BIFOCAL LENSES?
For everything explained above, we can already assume that the price of progressive glasses will be higher than that of glasses that only serve to correct myopia or astigmatism, or bifocal lenses, which do not have this gradual progression.