Squint


Squint

Description strabismus

To be able to understand the nature of this disease, you need to start with a little physical patterns of light propagation and wander a bit into the anatomy of the eye. The issue of strabismus is significantly more extensive and complex.

Light spread environment and the eye comes in the form of parallel rays. Eye functions as an optical apparatus which is composed of several kinds of lenses, each part has a different optical power(optical power is the unit of diopters and for the sake of completeness, it is the reciprocal of the focal length.
Focus is very simply said point at a certain distance from the lens, which is related to the refraction).

If the beam passes through such a system, it is ingeniously refracted so that the spokes pointing to one place (the center, the so-called central fixation). This is logical, and when you think about it, nor is it anything unrealizable.

But it should be understood that we look not only one eye, but we have two eyes. And to get the perfect image of its surroundings, which will correspond to reality, will not be blurred, moved, duplicated, and so forth, you need the perfect harmony of this mechanism for the two eyes.

Eyes are a landing station that will record images and the ability of our brain is that the pictures of the one and the other eye together in one single. This creates a perfect surround sensation. Such a phenomenon called binocular vision (bi = two, ocular = eye).

The ability of binocular vision is innate, it begins to develop immediately after birth. During childhood, this ability develops and matures, the stabilization occurs at around the sixth year of age.

There are conditions that are necessary to make everything work as outlined herein. First and foremost is the assumption physiological development of the eye of a child during pregnancy, approximately equal to the refraction of both eyes (the same ability of both eyes refract the rays in one place, which is the same, corresponding, in both eyes), normal range of visual fields of both eyes intact visual track (it is information from the eye routed to the relevant parts of the brain, where they are properly processed), properly functioning extraocular apparatus (4 straight muscles – upper, lower, inner and outer + 2 muscles oblique – top and bottom) and the intact brain function.

If all these conditions are met, it ensures seamless vision. If you are not satisfied, there aredifferent variations. We are here in this article we will discuss deviation, which occurs due tosquint or strabismus.

Strabismus is a condition where the axes of vision of both eyes are not directed simultaneouslyto a fixed object. Such an axis can be imagined as a straight line passing through the center of the pupil into the posterior pole of the eye. In the case of a normal vision, these axes are mutually parallel. For strabismus they are in principle axes intersecting.

This criterion is one of the evaluation elements for dividing strabismus, as such, is not uniform. It can be divided according to several parameters.

If we are interested in the cause of strabismus, then there are two large groups – strabismuskonkomitující (souhybný) where the fine muscles around the eyeball, but it is a violation of their co-ordination in the brain, and strabismus inkomitantní in which the infringed right mobility (motility) of muscles .

The direction strabismus divided strabismus convergent (strabismus convergens), wherein the axis šilhajícího lugs bent outwardly and diverging (strabismus divergens), wherein this axis is oriented in the contrary.

If the fact that the axes of the two eyes are not parallel, this condition is subjectively perceived asdouble vision (diplopia =). This happens because the light rays on the retina stimulated points that do not correspond together – that is, they are not stored at the same location in both eyes.

Yet it must be emphasized that squint may be either one eye or both eyes. If such a state, there are basically three ways with the brain can deal with. The first way is suppression, in other words, suppression of perception šilhajícího eye. It is the mechanism that is temporary, and if the squint properly adjusted (corrected), suppression disappears.

The second option, which is not so favorable is amblyopia (amblyopia). This is the result of suppressing the perception of the eye, squint, and that it is also the most serious complication of strabismus.

The last option is that if you create eye in place of the sharpest vision where physiologically occur.Healthy eye has a so-called central fixation – fixing the beams to place the sharpest vision, the macula in the retina. Eye to squint, has rays of this axis tilted, so it is difficult to direct them to the right place. This is a new position created in the vicinity of the original. What makes this more distant from the site of sharpest vision, the eye damage is worse.

 

Individual types of strabismus

Konkomitující strabismus – for this species is typical strabismus deviation equal in all directions perspective. We see him mostly in children, develops in the first two years of life.

It is caused by developmental defect during pregnancy or failure of sensory and motor functions of the eye. There is no exception that arises at dalekozrakého child that does not have its defect revised (corrected) glasses.

When konkomitujícím strabismus may happen that one (possibly both eyes) squint inwards (so called esotropia), outward (entropy, rarer case) optionally up (hypertrophy).

Inkomitantní strabismus – squinting, which is caused by malfunction of one or more ocular muscles. Such a failure may arise either poor innervation of muscles or muscle paralysis.Poliomyelitis can be both acquired and congenital.

This type occurs mainly in adults. Typical is his limiting movement of eyes in the direction of the affected muscle, eye squint into different directions with different deflection (that differs from konkomitujícího strabismus, where the skew is equal in all directions).

People often feature eye muscles are replaced by the position of the head, such as a slight bow, which might not even be at first glance downright obvious. Causes muscle movement disorders are a few, but all of its complexity beyond the scope of this text and understanding of the issue are irrelevant.

 

Risk factors for strabismus

Risk factors include any violation of the fundamental conditions that must be met so that it has developed a full binocular vision. This may be e.g. poor development oculomotor system during pregnancy, the different optical power of the eye (for example, one eye may be normal, and the second hyperopic or myopic), with a heel range of visual field, impaired function of the visual pathway and ultimately disturbances in the brain.

 

prevention of strabismus

Do not underestimate squint, especially in children, because of the risk of amblyopia.

 

Signs and symptoms of strabismus

Subjectively or objectively observed changes in eye movement, or complaints about double vision.

As in younger individuals, and the elderly may be a sign that something is not right as the fall down the stairs. This is the reason that people who suffer from double vision, have impaired awareness of your surroundings and know what is fact and what is the “second image of reality” – so došlápnou example on the step, which is a reflection of the real step.

 

treatment of strabismus

Can be either conservative or surgical. Conservative therapy is to modify squint special lenses,prisms, which have the property that they can refract light rays so as to seek to place the sharpest vision and eye so did not have to “help out” šilháním.

Children who are corrected by glasses should try as much as possible try squinting eye. This is often done by covering the healthy eye náplasťovým occluder. Eye, squint which is gradually trained.Because children can be traumatic occluder, used alternatives – painting, beading and so on.

Surgical treatment is focused on eye muscles, which changes the length so that the eye would ideally be in the physiological status.

In any case, the correction should be done in early childhood, when the chances for a complete cure vision highest.

 

How do I help myself

There are alternatives to help in this case alone, it is always necessary supervision and proper treatment. It’s good to lead a child to load eyes – small handicrafts and the like, or try squinting eye discarding healthy eye – that Cover healthy eye patch occlusion.

 

complications strabismus

The most serious complication of strabismus is, as mentioned above, amblyopia. It develops most often in children under six years of age and unilateral strabismus. It arises from the fact that long-term brain suppresses the sensation of the eye that squint. In practice, it appears that the information it receives squinting eye, brain drains and thereby protects against the negative perceptions that arise in connection with double vision. If such a patient is then examined, it is found lunge visual field in the central region – this means that in the central part of the perceived image is blank. But the paradox is that the eye is anatomically adapted perfectly normally.Amblyopia can be both one-sided and double-sided and its cause may be associated only with šilháním may be congenital.

A further complication in connection with double vision changed perception of the surroundings. A related example downs miscalculation in space, the inability to read or nausea.

Other names: strabismus, squint

Share your experience: