Myopia is a disorder in which the subject is unable to correctly focus on distant objects. Therefore, he perceives them in a blurred and indefinite way, producing discomfort to the patient.
Usually the light that we receive must go through a series of layers that form our eyes until we reach the optic nerve:
- First, goes through cornea and a liquid called aqueous humor.
- Then pierces the lens and a liquid substance, the vitreous humor. Likewise, the image is projected towards the retina, the posterior layer of the eye. On the other hand, the image that is sent is the other way around, it is the brain that processes it and turns it around.
- Finally, the light is captured by the photosensitive cells of the retina and it becomes a nervous impulse to be received by the optic nerve.
However, when the image is not projected onto the retina correctly, we find visual alterations. In the case of myopia the light is projected just in front of this layer and the more distance there is, the patient will have more difficulty focusing or more diopters.
This alteration it may be because the cornea is too domed or that the eyeball is larger than usual. The most frequent causes are:
- Genetic heritage, the disorder is transmitted dominantly.
- Pathological. Some diseases can cause temporary or permanent visual damage. For example, cataracts, keratoconus or diabetes 2.
- Environmental or the conditions of the development environment.
- Toxic. Consumption or exposure to certain toxic substances can also lead to vision problems.
The patient You may also have headaches and red eyes often during myopia. As a general rule, myopia is detected in revisions of periodic visual acuity or when the patient begins to feel visual alterations.
On the other hand, The treatment will depend on the characteristics of your myopia. We can classify them according to the following criteria:
- Palliative They counteract the alteration temporarily. The use of glasses or contact lenses. In the case of contact lenses, the time of use and conditions must be controlled in order to avoid side effects.
- Definitives We are talking about surgical interventions, especially refractive surgery.
Use of refractive surgery
Depending on the technique and modifications to be made We can distinguish between different types of intervention:
- LASIK . A small part of the outer layer of the eye or cornea is sectioned. After modifying the corneal tissue with ultraviolet light to correct the refraction of the light. Finally the removed tissue is replaced.
- PRK. With the help of a microllaser part of the cornea is sectioned in order to achieve its applanation. Thus, the projection of light on the retina is corrected.
- Radial keratotomy. A series of small cuts are made in the cornea that reduce its bulging shape. Currently it is a class of obsolete interventions.
Side effects of refractive surgery
Also, the patient may suffer a series of side effects or unwanted after the medical operation. The most common are the following:
- Discomfort and sensitivity to light. The subject can also see points or beams of light at the ends of his field of vision.
- Periodiction of myopia. However, a reduction in the number of diopters presented in the patient before the operation.
- Perforation of the cornea. It can also produce an infection of the lesions created in this layer.
- Farsightedness or projection of the image behind the retina.
- Increased intraocular pressure. This alteration is a high risk factor when developing glaucoma.
In any case, if you experience any of these side effects or suspect that your visual acuity has decreased, It is recommended that you check your eyes as soon as possible.