Ametropia

The term ametropia is used to describe a number of different, non-standard or sub-optimal conditions of the visual sense . In the narrower sense, this term refers to ametropia , in ophthalmic optics the term for an optically non-ideal eye. In a broader sense, every deviation of an individual quality of the visual sense from the ideal or normal value can be described in this way. Normal measured values ​​are sometimes also considered ametropia if, as in the example of ametropia, the norm does not correspond to the ideal.

In the broader sense, ametropia is defined as certain suboptimal or non-standard performance in the areas of visual acuity , accommodation , color vision , eye motor skills or twilight vision .

Normal vision

The concept of normal vision has been introduced as a counter-term to ametropia . Depending on the sensory quality considered, either an ideal value (such as emmetropia as opposed to ametropia) or a physiological normal value in the sense of a deviation of less than two standard deviations from the average ( normal variant ) is meant . When assessing fitness to drive and classifying incapacity for work and visual impairment, legislators or insurers use fixed limit values ​​that correspond to an expert consensus on the requirements of driving, gainful employment and everyday life. The pair of terms ametropia / normal vision does not matter.

Forms of ametropia

• The refractive error refers to the deviation of the refractive power of an eyeball from the ideal value, that is the state of refraction ≠ 0. These include nearsightedness (myopia) , the farsightedness (hyperopia) and astigmatism (astigmatism) .
• Presbyopia ( presbyopia ) is the physiological decrease in the ability to accommodate with age.
• Heterophoria is called a hidden ( latent ) squint , often without a pathological background.
• Angular ametropia is a scientifically unrecognized art term from ophthalmic optics that is another term for heterophoria .
• Strabismus ( strabismus ) describes a pathological disorder of the eye muscles
• Amblyopia is a functional weak-sightedness without an organic cause as a result of inadequate stimulation or imaging quality of the affected eye (for example, in the case of strabismus), which persists even with optimal optical correction.
• Asthenopia is a complex of complaints that is not precisely defined , often affecting younger people. B. can be triggered by uncorrected ametropia or latent squint.
• The Hemeralopie ( night blindness ) is an abnormal reduction of vision in the dark.
• The color ametropia in their congenital or (more rarely) acquired form are deviations from normal color perception, the best known being red-green visual impairment and the extreme being achromatopsia ( color blindness ).

Critique of the term

The terms of ametropia as well as normal vision can be misleading if, as in the case of ametropia, heterophoria or presbyopia, they suggest a defect that does not actually exist. On the one hand, this creates unfounded concerns and, on the other hand, conceptually blurs the line between actually pathological conditions. In scientific ophthalmology, both terms are therefore avoided as far as possible.

See also

• Visual impairment - unspecified, permanent or temporary impairment of vision
• Standard observer - in color theory , the average defined as normal sighted for the assessment of colors.

Web links

• Kindergesundheit-info.de - early detection of visual disorders and risks : independent information from the Federal Center for Health Education (BZgA)

Individual evidence

1. ^ Pschyrembel clinical dictionary. With clinical syndromes and nouns anatomica. = Clinical Dictionary. Edited by the publisher's dictionary editor under the direction of Christoph Zink. 256th, revised edition. de Gruyter, Berlin et al. 1990, ISBN 3-11-010881-X .
2. ^ Albert J. Augustin: Ophthalmology. 3rd, completely revised and expanded edition. Springer, Berlin et al. 2007, ISBN 978-3-540-30454-8 , p. 580.
3. ↑ Information from the Techniker Krankenkasse
4. ↑ Information from the University Hospital Tübingen ( Memento of the original from June 14, 2014 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  

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