Farsightedness (hyperopia) is, next to myopia, the second most common sight defect. Farsightedness is classified as spherical defects related to the incorrect refraction of light in the optical system. Sometimes farsightedness goes undiagnosed for a long time, because thanks to the compensatory abilities of our eyes, it may not have any characteristic symptoms.

Farsightedness( hyperopia , Latinhyperopia ) is mainly observed in children. Initially, they suffer from the so-called physiological farsightedness, associated with the continuous development and shaping of the eyeball and the entire optical system. It should disappear over time, but sometimes hyperopia in children may become persistent. In adults, farsightedness can rarely be caused by long-term diabetes, which can damage the blood vessels in the retina.

Under physiological conditions, the image is created perfectly on the retina thanks to the refractive system of the eye. Farsightedness occurs when the image is not formed on the retina, but behind it. A farsighted eye is one that has a reduced anteroposterior dimension (the eyeball is too short) or the optical system of the eye has too little breaking strength (abnormal cornea or lens abnormal). Thanks to the ability of our eyes to accommodate, as a result of changing the shape of the lens, even with a too long eyeball, the rays can be focused closer, so that the image can be formed on the retina, not behind it.

How does farsightedness manifest?

Typically, farsightedness will manifest itself as clearly seeing objects at some distance from the eyes, while objects lying closer will appear blurry. Over time, however, as the disease progresses, both near and far vision may be impaired. Symptoms will be different in severity between age groups because the ability of the eye to accommodate decreases with age. In addition, people with farsightedness may develop headaches, double vision, strabismus and eye pain. Headaches quite often accompany farsightedness, unfortunately they are non-specific, so you should always bear in mind that a patient who reports such ailments may have an ophthalmological problem, and farsightedness should be included indifferential diagnosis.

breakdown hyperopia

Farsightedness can be divided according to the clinical picture and the degree of advancement. Clinically, farsightedness can be simple, pathological, or functional. Simple farsightedness occurs for no apparent reason and is due to biodiversity. Pathological farsightedness can occur as a result of illness, trauma, or abnormal development. Functional farsightedness, in turn, results from an impairment of the eye's ability to accommodate, which may result from some paralysis.

Due to the severity of farsightedness, we can divide it into low, when its value does not exceed +2.0 diopters, moderate, when the values ​​are between +2.0 and +5.0 diopters, and severe (high), when it exceeds +5.0 diopters.

How is farsightedness diagnosed?

Adults report to a doctor fairly quickly when visual disturbance or other bothersome symptoms start to interfere with their daily life.

The problem is small children who cannot talk exactly about their ailments. Their farsightedness is very often diagnosed when parents see the doctor after noticing that the child is squinting. Strabismus in an infant over three months of age should raise our concern. With farsightedness, we most often observe convergent strabismus. It arises when the eye tries to compensate for the defect through accommodation, which then triggers convergence. Convergence is the contraction of the medial rectus muscles of the eye, as a result of which the eyeballs point towards the nose, and we observe it as convergent strabismus.

An ophthalmological examination is necessary to diagnose farsightedness. The method of examining refractive errors based on the Donders rule is often used. During this examination, we check visual acuity while looking into the distance. The patient is placed on the lens frame starting with a strong converging lens and gradually less powerful lenses are put on. A measure of farsightedness is such a converging lens (with a value of "+") at which the patient sees acutely enough.

The Donders method cannot be used as the only diagnostic method in children, and in adults with strong accommodation, because we are not able to eliminate its influence on the test result. In this case, with farsightedness, strong accommodation will create apparent myopia, which will result in incorrect treatment.

Another method that allows you to avoid such mistakes is skiascopy (also known as retinoscopy), which is an objective examination. In order to perform this test properly, accommodation must be abolishedin the examined eye, it is called pharmacological paralysis of accommodation or cycloplegia. Cycloplegia is performed most often with the use of tropicamide, atropine and cyclopentolate (mainly in children). During the skiascopy, the doctor projects a beam of light onto the patient's eye, and then, while the machine is moving, he observes the direction of movement of the red light from the fundus, which can be seen in the pupil. In farsightedness, both of these directions will be consistent. After such an examination, pupil dilation may cause a short-term decrease in visual acuity or photophobia.

A very effective diagnostic method is autorefractometry, which also uses the principle of skiascopy. In order for it to be as objective as possible, before the examination, the accommodation should be disturbed, which could distort the results. The entire examination is carried out properly by a computer that adjusts the parameters to the optical system of the eye. The autorefractometer quickly calculates the necessary data and gives the result in the form of a printout, which shows possible refractive disturbances in both eyes.

Hyperopia: treatment

Farsightedness is treated with convex converging lenses. The oldest and best known is the spectacle method. In the event of strabismus, treatment should be introduced immediately, because the longer it lasts, the more difficult it will be to obtain satisfactory treatment results. In all cases of concurrent strabismus, full correction of hyperopia is recommended, and in the case of coincidental strabismus accompanied by hyperopia, the strongest plus lenses are recommended.

Strabismus prevents correct binocular vision, and the older the child becomes at the time of treatment, the more difficult it will be for him to adapt to the new conditions.

Lenses placed in front of the eye in the case of glasses enlarge the retinal image adequately to their power. In adults, glasses with a power difference of more than 2.0 D between the lenses cannot be used, because the size of the image formed on the retina should be the same or very similar in both eyes. In such a situation, it is necessary to correct the eye that "sees better" as much as possible, and in the second case to use the strongest possible lens, but sufficiently to stick to the above rule. The glasses should be 12 millimeters from the center of the cornea. In children, light glasses that do not break should be used. You also need to pay a lot of attention to the selection of appropriate frames. The nose and the back of a child are not fully developed yet, so you should use frames with soft and flexible temples to maintain a constantdistance between the lenses and the cornea.

Contact lenses are more and more often used by patients who most often choose them for aesthetic reasons. Contrary to glasses, contact lenses do not narrow the field of view. However, this method has its drawbacks. Some patients develop complications. We observe conjunctival complications mainly in allergy sufferers who mainly use soft lenses. These patients may often develop conjunctivitis of various etiologies. We observe corneal complications more often and can include, for example, mechanical abrasions to the cornea, damage caused by prolonged wearing of lenses, and sometimes even corneal ulcers. Therefore, proper hygiene and care of lenses and the eyes themselves are very important in this method.

There are also various surgical methods available in the treatment of farsightedness, which, depending on the center, differ in terms of advancement and innovation. These are largely laser surgeries that aim to modify the shape of the cornea, such as keratotomy, refractive photokeratectomy, LASEK or LASIK. However, not everyone can submit to such a therapeutic method. Laser refractive surgery is contraindicated in such situations as:

  • keratoconus
  • age under 18 (except for special indications)
  • low corneal thickness (most often<500 um)
  • recurrent conjunctivitis and keratitis
  • autoimmune systemic diseases
  • severe dry eye syndrome

Category:

Eye diseases and vision disorders