The prescription of the glasses depends on the diopters that we have. These are a unit of measurement that tells us if our eyes have vision defects that should be corrected with prescription glasses. In turn, they also refer to the prescription that the lenses that we use for that purpose must have. In short, it corresponds to the refractive capacity of the lenses used in glasses.
The way to determine if we have myopia, astigmatism or hyperopia is measured through the diopters. These represent a number that is related to the amount of correction that each patient needs through their glasses to obtain normal vision. In the case of myopia the lenses are concave and their power is negative, but in hyperopia they are convex and the power is positive. Astigmatism It can have both values, so that if a negative symbol appears in the patient’s review in this evaluation, they will have astigmatism and myopia, but if the opposite appears, they will present astigmatism and hyperopia.
In each of these disorders there is a diopter cap, and although in general they are not usually very high, they can evolve over time. Thus, in hyperopia and astigmatism you can reach maximum at 13 dioptersWhile in myopia it is possible to reach 25, and in tired eyes at least up to three.
Go to the ophthalmologist
Diopters are corrected through both eyeglass lenses and contact lenses. Now, to know if these have stopped or have increased the most correct thing is to go to the ophthalmologist. It must be borne in mind that the glasses replace the lack of vision but do not stop the evolution of the disorder, nor do they harm or worsen it according to the experts, but they have to be well graduated. Sometimes there comes a time in which diopters no longer evolve and the problem can be addressed through refractive surgery.
There are a number of symptoms that may indicate that we may have to change the prescription of the glasses and go to an ophthalmology consultation to tell us if it is necessary. For example, if with them we see blur at medium or long distance, if we notice that our eyes are noticeably tired when watching TV or reading for a long time, if we feel a headache especially around the eyes or perceive difficulties when carrying out tasks that require precision or short distances such as sewing, then it is advisable receive an expert opinion.