A person who has no visual defect – in clinical practice, a visual acuity of 1.0 is considered normal – is able to read 10 out of 10 optotypes, i.e. letters or numbers visible on a special chart in an ophthalmologist’s office, without any problems. There are even people who are able to read even lower rows and their vision can then be described as 1.25; 1.5 and even or 2.0.
1.0; 1.25, 1.5 or 2.0 are the parameters that determine visual acuity without correction. Are there situations where it is worth knowing your focus without correction? Of course.
Determination of visual acuity without correction should be performed prophylactically, for example, in children starting school. Even if the child does not report any vision problems and the parents do not notice anything worrying (headaches, eyelid rubbing, head spinning, reluctance to color, sitting too close to the TV), such a preventive diagnosis is highly advisable. This is because it may turn out that despite the lack of symptoms, the child is already developing a visual defect or eye disease.
Visual acuity testing without or with current correction should also be passed by driver candidates. A full ophthalmic examination with a detailed history will determine whether we can drive without glasses or contact lenses. If during the examination it is found that our eyesight requires correction, the driver’s license will be annotated accordingly in the form of a symbol written in the last box of the table on the reverse of the license:
The test of visual acuity in the current correction is performed when the patient has already worn glasses for many years and, when appearing for the test, does not even remember the power of his eyeglass lenses. The test allows you to determine your current visual acuity, and then check whether the visual defect has worsened or regressed. After many years of using the same glasses, another correction may be needed, and the patient will be surprised how much a small change affects the quality of vision.
Assessment of visual acuity without correction, with glasses and with the best possible correction is also carried out as part of the qualifying visit for laser vision correction.
