ICD codes for this disease: ICD codes are internationally valid medical diagnosis codes. They are found e.g. in medical reports or on incapacity certificates. H52
If your child is far-sighted, make sure that he always wears his glasses. This will prevent your child from squinting and developing a faint-eyed sensation.Dr. med. Mira SeidelArticle overviewForeignity
- Causes and risk factors
- Farsightedness in old age
- Examinations and diagnosis
- Disease course and prognosis
Foresighted are people who can not see sharp objects close. This is usually due to a too short eyeball. Then doctors speak of an axis hyperopia. Much rarer is the so-called refractive hyperopia: Here, the farsightedness is based on too little refractive power of the eye, that is, the ability of the eye to bundle incoming light rays is not sufficient.
The refractive power of the eye can be measured and is given in the unit Diopter. In farsightedness, there are plus values (with nearsightedness minus values).
About 20 percent of all under-30s are far-sighted. For most people, the power of the eyes is below +4 to +5 diopters (dpt). Only a few people have higher readings and thus an even more pronounced farsightedness.
Sharp vision near and far
In order to be able to see an object clearly, the light rays emanating from it must be refracted on the way through the eye so that they meet exactly on the retina. The closer the subject is, the stronger the refraction in the eye must be for a sharp image on the retina. The eye must therefore be able to change the refraction of light, that is, to be able to adapt the visual acuity to different distances. This ability of the eye is called accommodation.
The accommodation is made possible by a variable form of the eye lens. This is responsible (in addition to the cornea) for the refraction of light in the eye. The eye lens is suspended by fibers on the so-called ciliary muscles. As the muscles contract, the lens bends more sharply (becomes more rounded) and increases in refractive power. This allows close objects to be sharply imaged on the retina.
In contrast, when the ciliary muscles relax, the lens of the eye is stretched out, ie flatter - the refractive power decreases, so that distant objects are seen sharply.
In order to see an object that is in the center and near our eyes, the so-called convergence reaction takes place. The two eyeballs move towards each other, the pupils narrow and the refractive power increases due to a stronger curvature of the lens. Accordingly, the accommodation and the convergence reaction are coupled to each other.To the table of contents
Farsightedness means first of all that someone can not recognize sharp objects. In addition, the eyes must accommodate even in the long-distance, so tighten a little. The ciliary muscles on the lens are therefore permanently stressed. This mainly causes headaches. Other symptoms of hyperopia are:
- rapid fatigue of the eyes
- eye pain
- Burning eyes
- Conjunctivitis (conjunctivitis)
These symptoms are also summarized under the term asthenopic complaints. They are mainly noticeable in reading.
Since, anatomically speaking, the increase in refractive power and the movement of the eyes toward one another (convergence reaction) are coupled to one another, inward squinting is another possible symptom in farsightedness.To the table of contents
Farsightedness: causes and risk factors
The reason for the farsightedness may be either in a too short eyeball (axis farsightedness) or at a reduced refractive power of the lens (refractive hyperopia).
Axillary hyperopia is by far the most common: because the eyeball is shorter than normal here, the image is not sharply focused on the retina even at maximum accommodation - the incident light rays would only meet behind the retina in a common focal point. Therefore, people with farsightedness can not see nearby objects sharply.
In the distance, a person affected can indeed see sharp, but the lens must also be accommodated here, because their power in the relaxed state is not sufficient even for distant objects. Therefore, the ciliary muscles, which cause a curvature of the lens and thus an increase in refractive power, are constantly tense.
With the long-distance vision and a farsightedness of up to 4 dpt this is no problem for a young person. But in order to be able to see something sharp in reading distance (about 33 centimeters), a further 3-D refractive power is necessary. That means a total power of 7 dpt, which must be provided. This is in the long run by the eye not to afford and makes complaints.
In refractive hyperopia, the eyeball is normally long, but the power of the lens is lower than normal. The consequences are the same as in the Axial hyperopia.To the table of contents
Farsightedness in old age
How long-sightedness arises in old age, you will read in the article Presbyopia.