De México 664-979-2020     Toll Free 888-541-0202
 
 
De México
664-979-2020
Toll Free
888-541-0202

Astigmatism

What is Astigmatism?

View Video

In ophthalmology, the vertical and horizontal planes are identified as tangential and sagittal meridians, respectively. Ophthalmic astigmatism is a refraction error of the eye in which there is a difference in degree of refraction in different meridians. It is typically characterized by an aspherical, non-figure of revolution cornea in which the corneal profileslope and refractive power in one meridian is greater than that of the perpendicular axis. 

Astigmatism causes difficulties in seeing fine detail. In some cases vertical lines and objects such as walls may appear to the patient to be leaning over like the Tower of Pisa. Astigmatism can be often corrected by glasses with a lens that has different radii of curvature in different planes (a cylindrical lens), contact lenses, or refractive surgery.  In 1997 at the Codet Vision Institute, Dr. Arturo Chayet developed a nobel and now widely way to treat the astigmatism: Bitoric LASIK. Since then, Dr. Chayet have treated successfully thousands of patients with this approach.  Astigmatism is quite common. Studies have shown that about one in three people suffers from it. The prevalence of astigmatism increases with age.  Although a person may not notice mild astigmatism, higher amounts of astigmatism may cause blurry vision, squinting, asthenopia, fatigue, or headaches.  There are a number of tests used by ophthalmologists and optometrists during eye examinations to determine the presence of astigmatism and to quantify the amount and axis of the astigmatism. A Snellen chart or other eye chart may initially reveal reduced visual acuity. A keratometer may be used to measure the curvature of the steepest and flattest meridians in the cornea's front surface. Corneal topographymay also be used to obtain a more accurate representation of the cornea's shape. An autorefractor or retinoscopy may provide an objective estimate of the eye's refractive error and the use of Jackson cross cylinders in a phoropter may be used to subjectively refine those measurements. An alternative technique with the phoropter requires the use of a "clock dial" or "sunburst" chart to determine the astigmatic axis and power.

Established in 1986 · 1st IntraLASIK worldwide in 1995 · 1st Light Adjustable Lens worldwide in 2002
De México
664-979-2020
Toll Free
888-541-0202