Accommodation is the mechanical ability of the eye to increase the power of refraction and be able to focus images that are located between a distant point and a near point. Therefore, we can say that accommodative flexibility is the ability of the accommodation system to change from one visual level to another.
En Área Oftalmológica Avanzada We explain what the accommodation flexibility test consists of and what it is for.
What does the flexibility of accommodation measure?
Accommodation flexibility measures the ability and speed of the eye to focus correctly an object at a certain distance (far) and then focus on another object at a different distance (near). Accommodation flexibility refers to the power of the ocular structure to make rapid, repeated, and normal changes during accommodation.
What is?
The usefulness of this diagnostic test may depend on how the exam is performed:
- La monocular measurement of accommodation flexibility measures the ability of the ocular system to alternately change focus from a far distance to a close one.
- La binocular measurement measures the flexibility of accommodation, maintaining a balanced vergence.
How to perform the exam?
To measure accommodation flexibility it is necessary to use a +/-2D flipper. The flipper are lenses mounted on a kind of glasses with a handle, a part of the flipper has -2D lenses and when you turn it with the handle, +2D lenses are found. During the examination the patient must rotate the flipper with the handle to see through the two types of lenses.
At the time of the accommodation flexibility test, the patient must have prescription glasses on, there must be good lighting in the room and they must hold the chart at a distance of 40cm.
Monocular shape
The exam begins monocularly, usually starting with the right eye and then the left eye. The flipper is placed in front of the right eye on the side where the + 2D lens is located. Once the flipper is on, the patient should focus on the letters of the test closely or primer. When finished, the flipper is turned and the test is displayed again, but this time through the -2D lenses. This procedure must be performed consecutively for 1 minute.
Binocular shape
The binocular measurement of accommodation flexibility is performed exactly the same as the monocular measurement, except that the patient will observe through the flipper using both eyes simultaneously.
It is important that the patient does not change from one lens to another until the letters are seen clearly. In the meantime, the medical specialist should record the number of times the patient has flipped the flipper.
Normal values of accommodation flexibility
The results normal for an accommodation flexibility test are:
| AGE | MONOCULARS | BINOCULAR |
|---|---|---|
| 7 years | 6.5 | 3.5 |
| 8 and 12 years | 7 | 5 |
| Adults | 11 | 8 |
The reliability of this measure of flexibility of accommodation in children is usually relative. In general, due to its subjectivity, it is recommended to analyze the results around the entire context of the patient's ophthalmological evaluation, since during childhood, in no context, the result of this test can lead to a diagnosis.
