Medical expert of the article
New publications
Refraction study
Last reviewed: 04.07.2025
All iLive content is medically reviewed or fact checked to ensure as much factual accuracy as possible.
We have strict sourcing guidelines and only link to reputable media sites, academic research institutions and, whenever possible, medically peer reviewed studies. Note that the numbers in parentheses ([1], [2], etc.) are clickable links to these studies.
If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please select it and press Ctrl + Enter.
The study of refraction in children has a number of features. Firstly, it is not always possible to give a subjective assessment of vision, secondly, the influence of the habitual tone of accommodation determines the determination of different refraction in natural conditions and with drug-induced paresis of accommodation (cycloplegia). Until recently, atropine was considered the only reliable cycloplegic agent. In our country, a 3-day (2 times a day) instillation of atropine into the conjunctival sac is still considered standard cycloplegia. In this case, the concentration of the solution depends on age: up to 1 year - 0.1%, up to 3 years - 0.3%, up to 7 years - 0.5%, over 7 years - 1%. The negative aspects of atropinization are well known: the possibility of general intoxication, as well as prolonged paresis of accommodation. Currently, short-acting agents are increasingly used to induce cycloplegia: 1% cyclopentolate (cyclomed) and 0.5-1% tropicamide (mydriacil). Cyclopentolate is close to atropine in terms of the depth of its cycloplegic action, tropicamide is significantly weaker, and is rarely used to study refraction in children.
To study refraction in children, objective methods are mainly used. The oldest of them, but still of great importance, is skiascopy with a flat mirror. In children aged 3 years and older, automatic refractometry is also used. Subjective refraction testing (determination of the optical power of the lens with which the highest visual acuity is possible) is usually carried out from the age of 3. In this case, it is determined first by silhouette pictures, and later by "E" tests, Landolt rings and letters.
Visual acuity in children without eye pathology can vary widely. Conventionally, the lower limit of normal visual acuity at the age of 3 years can be considered 0.6, at the age of 6 years - 0.8. Much more important for identifying eye pathology is not the same decrease in visual acuity in both eyes, but its difference in the two eyes. A difference in monocular visual acuity between the eyes by 0.1-0.2 should cause concern, in these cases an in-depth examination is necessary.
[