Refractive Surgery: Surgical Techniques for Correcting Vision Defects
In recent years there have been significant advances in the surgical treatment of vision defects (myopia, hyperopia and astigmatism), especially with the introduction in the late eighties of the excimer laser, which represented a revolution in the field of Ophthalmology.
Are you nearsighted, farsighted or have astigmatism?
Briefly review the different types of refractive error or defect of sight. Basically, these defects are classified by the location of the image on the retina or innermost layer of the eye, which is collecting the images projected from the pupil:
Myopia
We speak of myopia when the focus of the images are produced in front of the retina. This produces a blurring of distant objects, and therefore the patient does not look good from afar.Farsightedness
We speak of farsightedness occurs when the focus behind the retina. In this case, the blurring of distant objects is often called compensated lens accommodation and blurred vision occurs when trying to focus on close objects. The patient can not see well up close.
Astigmatism
Finally, astigmatism is caused by a difference of curvature of the meridians or main axis of the eye and the focusing of images on the retina does not occur at a single point but at two different points. The blurring affects both distance vision as near vision and will be of greater or lesser extent depending on the position of these two points of focus on the retina.
credit to: Dr. Salvador Pertusa MartÃnez