Hyperopia( hyperopia) is the most common refractive abnormality and occurs in about 50% of people. In this state, the focus of the optic eye system does not fall exactly on the retina, but is behind it. This leads to characteristic symptoms and the need for consultation with a specialist in ophthalmology.
- 1 Why hyperopia occurs. This + or -
- 1.1 The nature of hyperopia
- 1.2 What are the causes of hyperopia:
- 1.3 What pathological changes are possible?
- 1.4 What are the symptoms of hyperopia?
- 2 Farsighted species
- 2.1 For the onset period:
- 2.2 For severity of
- 2.3 Behavior:
- 3 Other answers to questions about hyperopia
- 3.1 How is the diagnosis made?
- 3.2 What can go wrong?
- 3.3 How is hyperopia treated?
- 3.4 How to prevent hyperopia?
- 3.5 What are the recommendations after the diagnosis?
Why there is hyperopia. This is + or -
First, we answer the question, which for some reason is asked by many.
The nature of hyperopia
The eye with normal refraction is emmetropic - it's a healthy eye. In it, the image of the observed object, whether close or far, is formed on the retina. Due to the ability of accommodation, the lens constantly changes its shape. What makes it possible to get the ability to constantly maintain a clear image, regardless of the distance at which the object is observed. When looking at infinity( more than 5 meters), the emmetropic eye sees spontaneously, without resorting to the tension of the ciliary muscle for accommodation.
When the image of the observed object does not focus on the retina, it can be seen blurry and fuzzy. This condition is called ametropia or refractive anomaly.
The concept of ametropia summarizes all refractive anomalies: hyperopia, presbyopia, nearsightedness and astigmatism.
Correction of these anomalies is accomplished with corrective glasses, contact lenses or refractive surgery.
As a rule, these states are two-sided symmetrical( both eyes see equally badly).But if there is a difference in refractions in both eyes, then they say about such a disease as anisometropia.
The degree of ametropia is determined by the values of the corrective lenses required for restoring emmetropia and measured in diopters.
What are the causes of hyperopia:
- Weakening the power of accommodation. Usually this occurs with age, up to a complete loss of the ability of the lens to change the curvature( about 65 years);
- "Small Eye" - reduced eyeball on the front or rear axle.
What are the possible pathological changes?
Usually, no objective pathological changes are observed. But with a strong farsightedness, there may be a slight degree of hyperemia and a slight blanching of the nipple of the optic nerve - a condition called hypermetropic pseudoneuritis.
What are the symptoms of hyperopia?
People suffering from hypermetropia, well see into the distance, although constantly straining the ciliary muscle for accommodation( with a healthy eye, it is relaxed).Hence the name - "farsightedness".
Kinds of farsightedness
Some believe that the concept of hyperopia includes different types of diseases, but it is not. This is one disease that is simply classified according to the characteristics given below.
For the period of the offensive:
- natural physiological far-sightedness in children - the natural farsightedness that is observed in infants before their eyes grow sufficiently;
- congenital, also seen from infancy, but does not occur in the future, due to the small size of the eyeball or weak lens.
- age-long-sightedness - begins to manifest with age( more often after 45 years), due to loss of ability to accommodation.
The severity of
- is weak - 2 diopters( diopters);
- average - from 2 to 5 diopters;
- is strong - more than 5 diopters, which is very rare, and with hypermetropia more than 10 diopters the state already borders on microphthalmia( underdevelopment of the eye).
- Explicit hyperopia( hipermetropia manifesta) - measured by subjective method of refractive examination. Before the eye is placed the strongest( +) glass, with which the patient sees better. If at the same time vision is achieved at the level of 1.0 - 1.5, then this indicates an obvious hypermetropia;
- Farsightedness is complete( hipermetropia totalis) - after atropinization( instillation of atropine into the eye, which leads to paralysis of the ciliary muscle, respectively, accommodation).It is always easy to install;
- Hidden hyperopia( hipermetropia latents) - calculated by subtracting the apparent hypermetropia from the full. That is, it is a hyperopia, which is compensated by muscle tension and, accordingly, accommodation. The younger the patient, the greater the proportion of latent farsightedness and vice versa. In 60-year-old patients, the latent farsightedness completely changes into an explicit one, because of the reduced ability to make accommodation.
Young patients with this refractive anomaly see clearly, both far and near. But for this, they subconsciously constantly strain the ciliary muscle for accommodation when looking into the distance and, respectively, when looking close. This continuous tension of accommodation leads to hypertrophy of the ciliary muscle. Prolonged overstrain due to constant accommodation( for example, reading) causes fatigue in this same ciliary muscle, resulting in accommodation asthenopathy - a weakening of the accommodation power. Complaints in this case:
- With long-term viewing near images become vague, fused, blurred.
- Feeling of pressure, heaviness, pain in the eyes and forehead;
- As a complication of uncorrected farsightedness, conjunctivitis, blepharitis, and keratitis often occur.
Visual acuity at low and medium-foresightedness at a young age of 1.0 or more, that is, does not require correction. But with age, vision begins to fall, and a person already needs correction of apparent farsightedness, in order to adjust the clarity of vision first to the near, and then to the distant one. With strong farsightedness at a young age, even if the eyesight is good, correction is required to prevent the possible development of strabismus.
Other answers to questions about hyperopia
How is the diagnosis made?
The diagnosis is based on the history and data from ophthalmological studies - refractometry.
What can go wrong?
Hyperopia is not difficult to diagnose and easily distinguished from other diseases with similar symptoms.
How is hyperopia treated?
Farsightedness correction is performed using glasses with collective convex( plus diopters) lenses. Young people are corrected only by their apparent farsightedness, i.e.appoint such( +) lenses, so that the eye could see better into the distance. In old age, you may need to write out two pairs of glasses - one for correcting only for obvious farsightedness( worn constantly), while others for correcting simultaneous presbyopia and also obvious farsightedness( worn to work near).
At states after removal of the lens( aphakia), a strong farsightedness is obtained, because the lens had a strength of up to 33.06 D( in a state of accommodation).The apoptosis can be corrected using the collective lenses( +) 10-12 Dpt, set before the eye. This range in diopters here depends on the distance between the lens lens and the cornea, as well as from the level of refraction to the removal of the lens.
Hyperopia can be corrected not only with the help of glasses, but also thanks to the use of contact lenses. They are represented by a wide and sufficient series of diopters in our time. This in some cases can be very convenient.
Also modern methods such as refractive surgery, incl.laser correction, able to eliminate the manifestation of myopia in most cases.
How to prevent hyperopia?
Unfortunately, at present there is no effective prophylaxis of this disease, in addition to general recommendations for the eyes - regular rest, avoiding prolonged work at the computer, reading, etc.
What are the recommendations after the diagnosis?
After diagnosis and determination of the severity of hypermetropia, it is necessary to evaluate whether adjustment is necessary with the help of glasses, lenses, laser surgery, or it can be postponed. It is important to know that without the correction of hyperopia, a convergent strabism often develops. This is due to the need for permanent accommodation, which in turn causes a constant tension in the form of convergence( reduction of both eyes).With hyperopia often develops glaucoma in the elderly. If you do not fix hyperopia, it can also often be the cause of conjunctivitis and blepharitis.