Autorefractometry - what is it and how it is conducted?
The examination of the fundus by means of dilating pupils of drops is a thing of the past. The outdated technique is replaced by the latest computer equipment. For sure, those who are forced to wear glasses or lenses have repeatedly heard the word "autorefractometry".What it is? Let's try to understand.
What is autorefractometry?
Autorefractometry is a computer procedure that examines the cornea of the eye in order to determine such diseases as nearsightedness, farsightedness, astigmatism. The beauty of this procedure is the speed and accuracy of the result. The device accurately and in a short time determines what the refraction of the eye is. This allows you to pass the procedure to adults and children. What is this procedure? Let's discuss the issue in more detail.
Refraction of the eye is a complex process that is caused by a living optical system. In other words, the human eye is too complex. We can see because the light ray penetrates the cornea, then it reaches the anterior chamber and the lens, and only then the vitreous body, which refracts the light so that it focuses on the retina. An interesting fact: at the moment when light enters the retina, the image is perceived in an inverted form, and only after it is transformed into pulses, a familiar image appears before us. If not for this property, then the person would perceive the world upside down.
If we consider the very word "refraction", then it will denote the ability of refraction of light by the eye. In order to denote refraction, a measurement system was introduced, such as dioptries. If we are talking about the measurement of refraction in the office of an ophthalmologist, then the clinical effect is implied, while in a natural environment the refraction will be natural, physical. Clinical research allows you to take into account accommodation. Thanks to this ability, a person has the opportunity to focus the view on the subject, regardless of its distance. The tests conducted in the doctor's office allow to identify the accommodation and determine how thoroughly this function is performed. Thus, it can be concluded that such autorefractometry in ophthalmology. This is an objective method of assessing the features of the cornea and its ability to absorb and reflect light rays.
Methods of investigation
Eye refraction is the basic concept for the ophthalmologist. It is due to the indices of the autorefractometry carried out that it is possible to detect deviations in the functioning of the visual apparatus. Therefore, this procedure has gained incredible popularity in clinical medicine. The survey is impossible without a special device - a refractometer. This device independently conducts the test and gives the result, for what, in fact, and carried out autorefractometry. The interpretation of the result is carried out by an ophthalmologist. He looks at the refractive index values, determines the diameter and functionality of the cornea, and calculates the radius of curvature deviation.
In order for the result to be accurate, it is necessary to exclude all eye irritating factors. This is necessary in order to keep the eye calm, and nothing hindered him, because excessive muscle contraction can lead to the wrong result, which will lead to unpleasant consequences. To avoid this, the patient is offered to focus on a picture that is very far away. An interesting fact: earlier in the quality of such a picture a simple point was used, now in the new apparatus there is a picture of a ball or a Christmas tree, which allows the apparatus to determine the parameters more accurately.
Principle of operation of the
At the time when the patient is focused on the image, the doctor starts the device, and autorefractometry begins. What it is, the researcher may not even understand. For him, the process will be painless and will not cause discomfort. The infrared ray sent into the eye is refracted several times, until it reaches the eye fundus and retina. After that, it seems to be reflected from there and comes back. The time for which the ray returns is also the main parameter. This technique became available only with the advent of a refractometer, because man can not cope with this task.
Advantages of autorefractometry
Mankind has long appreciated the benefits of autorefractometry. What it is, it is worth to learn to everyone, because it allows you to evaluate the initial stage of deformation of the eye and notice abnormalities. Autorefractometry, the norms of which are clearly prescribed and indicated, is easily carried out in large diagnostic centers, so try to get an appointment with a doctor who has the apparatus mentioned above.
Also great pluses of the procedure are:
- confirmation of hyperopia and myopia;
- clear parameters;
- possibility of obtaining anisometropia data and its degree;
- speed and accuracy of the study.
Errors and nuances
The only nuance that must be taken into account before performing autorefractometry is the penetrability of light through the cornea. The point is that the procedure will be useless if there is a clouding of the cornea or other part of the eye. This is not surprising, because the main criterion for evaluation is the speed of return of the light beam, which means that the purity of the experiment depends on the initial state of the organ of vision.
Measurement of the return speed of a beam of light makes it possible to obtain a clear and reliable result. At the moment, this procedure is recognized as the most accurate of the existing ones. Having dealt with such a concept as autorefractometry, what it is and how it is carried out, you can safely go to see an oculist.