Presbyopia, also known as tired eyesight, is a natural and inevitable physiological process that 100% of people will suffer to a greater or lesser extent from 45 years of age. This process consists of the loss of elasticity of the crystalline lens and, with it, of the ability of the eye to correctly focus on nearby objects.
Due to its nature, presbyopia can appear associated with refractive defects such as myopia or hyperopia and this causes its symptoms to be different. In the case of a presbyopic patient (with eyestrain) who wants to undergo a myopia operation, it is very important that he or she knows these implications so that the results of the operation meet their expectations.
Emetropia (normal vision) + presbyopia
Far vision: It remains excellent even if presbyopia reaches its maximum degree.
Close vision: With the appearance of presbyopia, it is increasingly difficult to focus on nearby objects and at its maximum degree it can even affect intermediate vision.
Myopia + presbyopia
When dealing with two phenomena of an independent nature, it can be said that myopia does not prevent the appearance of presbyopia but does “camouflage” the appearance of its symptoms.
Far vision: Without correction is blurred by myopia. Presbyopia does not influence.
Without correction: Depending on the degree of myopia, presbyopia can be totally or partially compensated. The greater the degree of myopia, the better the near vision.
With correction: In case of correcting myopia, whatever the means (glasses, contact lenses or surgery), the compensation disappears and therefore, presbyopia usually manifests with blurred near vision. This is why a myopic with presbyopia removes his glasses to read.
Myopia operation in patients with presbyopia.
It is important that the postoperative expectations of the patient are consistent with the results obtained. In the case of patients in which their nearsightedness compensates and at the same time “camouflages” presbyopia, it should be understood that when far vision is corrected so as not to depend on glasses or contact lenses at all times, the symptoms of underlying presbyopia will appear. The use of reading glasses is necessary.
The operation of myopia for patients in the age close to the onset of presbyopia or with very incipient presbyopia may have, according to the surgeon, peculiar characteristics that make use of ocular dominance. For example, in a myopic patient of 43 years who has not yet developed presbyopia it is very likely that in the operation the surgeon makes the decision to leave the dominant eye (which predominates in distant vision) emmetropic and the reading eye (predominant in the near vision) somewhat myopic (-0.25 or -0.50) to compensate for the incipient presbyopia and postpone the need to wear spectacles close up. With this technique, the brain is able to dissociate the images it receives from the dominant eye and reading eye and achieve a correct binocular vision.