What is astigmatism?
El astigmatismo es un defecto de visión que afecta a cerca del 15% de la población general. Astigmatism is a vision defect that affects about 15% of the general population. It may be isolated or associated with other refractive errors ( myopia , hyperopia ).
What should astigmatism?
Astigmatism is caused by irregularities in the curvature of the cornea, such that the refraction varies between “meridians” of the eye.On the optical plane, these irregularities cause the image of a point is not exactly the image of a point, but an area between two zones and back.
Thus, the eye is constantly astigmatic blur, and attempts to correct it through accommodation, that is the contraction or stretching of the lens (a lens that is located within the eye and serves to focus images) so that one of the two focal areas are placed on the retina, allowing you to see clearly a part of the object in focus.
When eyestrain fault accommodation at the end of the day, etc., the person with astigmatism again sees all blur.
Forming astigmatism, congenital
They tend to be regular, bilateral and symmetrical, and little change throughout life.
Astigmatism acquired (trauma, diseases of the cornea)
They tend to be irregular and likely evolution.
What types of astigmatism are what are the symptoms of astigmatism?
The decrease in visual acuity is very variable. Sometimes it is well tolerated, but the astigmatism can be very harmful to vision, especially in children, which can lead to visual defects incorrigible. In young people, astigmatism usually detected by chance in systematic reviews.
With age, the failure mechanism of accommodation brings up the visual problem. Generally, there is a lack of sharpness in far vision, which can be confusing features patent numbers or letters (“N” instead of “H”, for example), the visual acuity values far vision successive examinations are variable, depending on the state of eyestrain. Near vision is affected much less.
Often there are other minor signs: redness, pain when the brightness is excessive headaches by prolonged fixation, or, more rarely, chronic inflammation of eyelids or double vision astigmatic eye.
Can astigmatism be a sign of other eye disease?
Certain eye diseases can manifest astigmatism progressive, in particular a corneal disease keratoconus, where the cornea is taking an increasingly more conical.
How ophthalmologist diagnosed astigmatism?
The ophthalmologist verifying visual acuity for distance vision and near, and controls the exact degree of astigmatism using a device called a refractometer, letting you know the type and degree of astigmatism that have each, to prescribe optical correction adapted to each.
The ophthalmologist also look for associated anomalies, including possible eye diseases responsible for astigmatism.
What you should pay particular attention?
If you notice your vision deteriorates, check that corrective lenses are well adapted to the view. If the vision is changed abruptly or quickly, consult an ophthalmologist.
How do I correct an astigmatism?
There is no eye drops or other drug therapy cure astigmatism.
Depending on the level of activity and their own desires of each, and depending on the test that is done, the ophthalmologist can advise glasses or contact lenses, or propose one surgery .
Surgery refractive disorders is increasingly common in developed countries, given their good results and low complications. The most widely used today is called LASIK (stands for “laser in situ keratomileusis”) consisting of an initial cut on the cornea to obtain a sheet hanging, turn around and model the laser corneal bed, and finally in place reposition the corneal flap. The entire process takes place in a few minutes under local anesthesia. LASIK treats both astigmatism and myopia or hyperopia, but has limitations primarily by the number of diopters to correct.
In cases of irregular astigmatism, as shown accompanying certain corneal diseases such as keratoconus, LASIK surgery, at least for now, is contraindicated. These patients may benefit from the use of rigid contact lenses.In advanced cases of these degenerations may be necessary to perform a corneal transplant.
Should a mandatory corrected astigmatism?
The optical correction of astigmatism is mainly a matter of comfort, except in the activities in which safety is at stake, such as automobile driving, where it is compulsory to wear glasses or contact lenses.
Dr. Michel Maille , Specialist in Ophthalmology