Astigmatism – causes, symptoms, diagnosis,treatment

Thu, 17 Mar 2016

Астигматизмом является искажение зрительного
image, which is due to different refractive power
Some elements of the eye as an optical system. With this
There is no clear picture on the retinal disease.
Seen the subject.

The fact is that the lens and cornea of ​​normal healthy eyes
has a straight spherical surface. Astigmatism is characterized
violation of their sphericity, it is characterized by different curvature for different
directions: more convex in one direction and dense in
friend, as, for example, Uzbek melon torpedo.

As a result, the light rays that pass through the lens or
the deformed cornea is not focused at one point on the retina,
and at the same time in several. Thus, the eye perceives
The image is not clear. Basically, astigmatism is combined with either
farsightedness (also called hypermetropic astigmatism), or
with myopia (another name is myopic astigmatism).

Astigmatism is right and wrong. Wrong
astigmatism is most often acquired (corneal clouding
eyes, cicatricial changes). This form of the disease
characterized by the presence of different refractive forces on individual
areas of the cornea. Therefore, the visual image on the retina
has a different degree of clarity. Acquired astigmatism mainly
develops after surgery on the eyes and after
injuries.

Proper astigmatism is characterized by deviations of the shape of the eye in
area of ​​the cornea. At the same time, the main corneal meridians (i.e.
mutually perpendicular axes that pass through the center of the pupil,
one of which is peculiar to the smallest, and the other – the greatest
refractive power) have deviations from strictly horizontal or
strictly upright position, while maintaining mutual
perpendicularity. Depending on the combination of clinical refractions, in
main meridians distinguish between complex, mixed and simple types
astigmatism.

Astigmatism to a large extent always significantly reduces the sharpness
view. Astigmatism of small degrees can be met quite
often, and it does not have a significant effect on vision.

Astigmatism – diagnosis

This disease is determined using objective and
subjective research methods. In identifying astigmatism with
using the subjective method during visual acuity research
placed in a test frame in front of the eye
opaque shield with a narrow slit; at its rotation choose
such position of a gap at which the greatest sharpness is shown
view.

Due to the correcting glasses the refraction of this is determined
meridian. Perform the determination of the refraction of another major
meridian and visual acuity by moving the shield with a gap of 90
degrees As a result, the difference of the main meridians determines
степень astigmatism. To objective methods of determination
astigmatism include ophthalmometry, skiascopy and
refractometry.

Астигматизм – treatment

Today, there are three most common ways to correct
this disease:

1. Лазерная коррекция astigmatism. It is intended for
adults (from 18 years). The basis of laser correction includes LASIK –
operation, after which the patient has normal vision, without
or restrictions.

2. Points. They are the most popular correction method.
astigmatism, especially for children. In this case, points are used.
which have special cylindrical lenses.

3. Toric contact lenses. Used for correction
astigmatism low degree. When astigmatism is prescribed
training the muscles that are responsible for the accommodation of the eyes
(video computer vision correction, drug use
drugs, laser stimulation). Also recommend fortifying
activities that include douche, swimming and
massage.

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