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Children & ametropia - early detection

Children are curious and want to discover the world. Optimal development of the senses is the basis for this. Full visual development also includes the child being able to obtain a sharp image on its retina in order to achieve full visual acuity. This is only possible if the eye has no relevant refractive errors. Even toddlers and preschoolers can be affected by refractive errors that require correction. At this age, parents usually do not notice it yet, unless their child is squinting or looking very close at objects. It is advisable to detect these relevant refractive errors at an early stage, because then the therapy is much easier. If a defective vision is detected too late, full visual performance can sometimes no longer be achieved, even with the best glasses, contact lenses or surgery later in life. The phase of visual development is limited in time. From about 8 to 10 years of age, it is much more difficult to achieve full visual acuity in the case of late discovered defective vision, despite correction with glasses. Sometimes it is even no longer possible. Therefore, refractive errors in need of correction should be detected and treated idealy before the age of 5.

Causes of ametropia in children

Often defective vision is genetically caused, i.e. when one or both parents or other direct relatives such as grandparents, already wore glasses as a child or did not develop full vision in both eyes. However, it is not uncommon for a child to be the first in the family to have glasses, or for the child to receive glasses earlier than it’s parents did.

Some forms of strabismus are also associated with refractive errors, such as farsightedness. Children who are born prematurely are also more likely to have refractive errors. These children are usually sent for eye examinations by pediatricians. In addition, refractive errors are also more common with special eye diseases and systemic diseases.

Forms of refractive errors in children

Among refractive errors, a distinction is made between farsightedness (also called hyperopia), nearsightedness (myopia) and astigmatism. Anisometropia is a condition with a relevant unequal refractive power between the two eyes, for example, when one eye is very farsighted and the other is hardly farsighted at all. In children of preschool age, uncorrected farsightedness, anisometropia and astigmatism are the main causes of incomplete visual development. Nearsightedness, on the other hand, plays a more important role from kindergarten and school age onwards.

Nearsightedness (Myopia)

Nearsighted people are not able to see sharply in the distance. In the near they usually see sharply. The vast majority of children are farsighted or normally sighted in infancy, toddlerhood and often in preschool. Nearsightedness often develops at school age. Children’s eyes grow somewhat in length as they get older. However, if children’s eyes grow disproportionately, they develop myopia (usually axial myopia). Hereditary reasons play a role in this, but it has also been observed worldwide over the past decades that the proportion of nearsighted children and adolescents is increasing sharply. In large-scale studies it has been observed that natural daylight outdoors is essential for normal eye development, and that breaks between prolonged close-up work (e.g. reading, small-scale handicrafts, working on a tablet, etc.) are very important. Nevertheless, there are children who experience an increase in myopia. We can treat these children ophthalmologically with special eyeglass lenses (multisegment lenses), minimally dosed atropine eye drops or special daytime contact lenses to curb the increase in myopia. We will be happy to advise you and your children.

Farsightedness (Hyperopia)

In farsightedness, near vision is impaired. Especially in children (already in infancy and preschool age) it is very important not to miss higher farsightedness. The younger the child, the more vision development takes place at near distance. If a child is not able to see sharply at close range, the development of vision is impaired, so that despite anatomically normally built eyes, a lifelong permanent visual impairment can occur (a so-called amblyopia). Children with more severe farsightedness are very often prone to internal strabismus (esotropia), which, if left untreated, leads to a loss of three-dimensional vision and to unilateral vision impairment. Three-dimensional and binocular full vision are very important for many professions. Timely evaluation is essential if there is a family history of strabismus, if strabismus is suspected, or if an vision test was performed unsatisfactorily at the pediatrician’s practice. We as pediatric ophthalmologists therefore recommend a screening examination for all children between 1.5 and 2.5 years.


Astigmatism refers to a curvature of the cornea (and the lens) which is not ideal in from an optical point of view. As a result, points in the eye are not displayed on the retina as points but as lines. This leads to image distortions. The reason is usually that the cornea, which is most responsible for image sharpness, does not have an ideal round diameter and a perfectly round curvature, but is usually slightly elliptically distorted. In many children this is hereditary. Sometimes, however, the child is the first member of the family to have a corneal curvature in need of correction. By spectacle correction, a sharp image on the retina is usually possible. This means that the distortions can be optically corrected so that very good vision development is possible again. It is also very important for small and preschool children to recognize this defective vision at an early stage and to take care of it accordingly.

Amblyopia (amblyopia)

Amblyopia is a visual impairment occuring in childhood during the years of visual development secondary to a lack of stimulation respectively deprivation. It can be unilateral or bilateral. The vision performed is under the potential of the eyes condition. That means the vision performance can be improved up to the age of approx. 8-10 years with appropriate specialist treatment. The potential for improvement is greater the younger the child. After completion of the visual development at the age of about 8-10 years, rarely older than 12 years, the visual performance can hardly or minimally be improved even with glasses, regardless of the cause. In the case of severe, newly discovered refractive errors, full visual development, even with glasses, is sometimes no longer possible from about 8 years of age.

There are various reasons for amblyopia. Common reasons are strabismus, anisometropia or a combination of the two. There are also more rare reasons, for example drooping eyelids (ptosis), lens opacities (often congenital pronounced to minimal opacities, so-called congenital cataracts), corneal changes (e.g. in severe blepharokeratoconjunctivitis or herpes) or changes in the optic nerve.

For the treatment of amblyopia, spectacle fitting is essential in cases of refractive error. If only one eye is affected, patching therapy of the better seeing eye is necessary to promote the visual development of the weaker eye.

Unequal vision (anisometropia)

In anisometropia, the eyes have different refractive powers. Thus, it can happen that one eye is normally sighted and the other eye has a defective vision that requires correction. In children, anisometropia is usually not noticed without an vision test and examination of the eyes’ refraction, unless it is very severe and the child begins to squint because it can hardly see in one eye. If the unilateral ametropia is not noticed, the full visual capacity of the affected eye cannot develop due to the lack of a sharp image on the retina, and the result is unilateral amblyopia. Therefore, preventive examinations by the pediatrician are useful and important. In case of suspected ansiometropia, an immediate pediatric ophthalmologic examination should be performed.

Professional treatment of refractive errors

It is important that more severe refractive errors in infancy and childhood are detected and treated early in order to achieve complete visual development if possible. The refraction measurement of children’s eyes is demanding and requires a lot of experience and empathy in addition to specialist knowledge and technical skills, especially with younger patients. Pediatric ophthalmologists are skilled and experienced in working with children from infancy through adolescence.

An accurate examination of refractive errors in children requires special pupil dilating eye drops. Therefore, when making an appointment with older children, it is advisable to remember that near distance vision in particular is limited for 6 to 8 hours, i.e. reading is more difficult, and there is an increased sensitivity to glare due to the larger pupils.

Choosing the right children's glasses

Not only the correct prescription by an ophthalmologist is essential for the care of refractive errors, but also the choice of suitable children’s glasses. These should fit anatomically well, so that they do not slip on and off the nose even during romping around and sports. Especially for toddlers and children with strabismus or anisometropia, it is essential that the glasses do not slip and that they do not look over the frame of the glasses. The glasses should also not be too large, i.e. the frame should not rest on the skin. This often causes the glasses to fog and the children can no longer see through the lenses. As a result they don’t want to wear the glasses then or they take them off. There are also other reasons why proper eyeglass fitting is very important for children. Specialized children’s eyeglass stores will help you choose the right glasses. If you wish, we will be happy to assist you and your child in finding the appropriate specialist optician.

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