The eye with normal refraction is called Emetropic. The image of the observed object, whether close or distant, is formed on the retina. Thanks to the accommodation, the lens constantly changes its shape and its refractive capability, depending on the distance of the object being observed, so as to maintain the clear image. When the image of the observed object is not formed on the retina, vision is blurred, unclear. The condition is called ametropia or refraction anomaly. The term ametropia summarizes all refractive anomalies: hypermetropia, presbyopia, myopia and astigmatism. Correction of these anomalies is done through correction glasses, contact lenses or refractive surgery.
Nearsightedness (myopia) is a refractive anomaly where the focus of the optical system does not fall directly on the retina, but lies in front of it. As a result, remote objects are blurred and blurry. The muzzle can not or hardly focuses objects when they are at a distance. By contrast, nearby objects are clearly visible.
Causes of myopia
In any case, genetic factors play a significant role in the onset and development of myopia.
Undisputed are also the environmental factors during the development of the eye, i. up to about 21 years of age. It is believed that modern living conditions in enclosed spaces and constant viewing closely predispose the eye to myopia. In these cases, it is taken as a compensatory response of the body to constant focusing close, and then it manifests itself with low dioptres ie. there is a spasm of accommodation. It is expressed in the spasm of the lens muscles that are responsible for the accommodation and the lens is adjusted to see clearly at a close distance, which is expressed in minus dioptres. Therefore, when reading, writing, or using a computer, it is advisable to focus distant objects in a certain amount of time in order to relax the emotion, especially in children and students (where muscles are much more active than older and older adults, can easily fall into spasm).
Classification of myopia
According to the decrease in visual acuity and the number of dioptres needed to correct the condition, differ:
• Light myopia: 0.25-4 dioptres
• Median myopia: 4-8 dioptres
• Severe myopia (malignant or excessive): over 8 dioptres
Excessive myopia, as its name suggests, often increases with time, even after 20 years of age.
The most common symptoms
Symptoms of myopia can be:
Difficult view of distant objects.
Voltage when viewing remote objects
And in children: bad results in school, which is very often the first sign in young children who are afraid to complain about their vision problems. CryptoLogic.
How is a diagnosis made?
In order to establish with certainty that it is about myopia, and to what extent is it manifesting, a doctor-specialist should be examined. Diagnosis is done through correction glasses and a refractive chart or projector. An objective method for examining vision is by an apparatus called autorefractometer.
It is imperative to place drops to expand the pupil (cycloplegia) to block accommodation. spasm is removed and real refraction is determined. This way, dioptres are not given (hypercorrection) and prevention of further increases in minus dioptres due to hypercorrection.
Therefore, if your doctor fails to enlarge the pupils and once again check the eyesight of broad pupils, you must mandate this from him.
After 40 years of age, it is believed that the accommodation is lost due to thickening of the lens and the loss of its ability to change its shape, so older adults do not resort to pupil enlargement.
Prevention of myopia?
In most cases, myopia is associated with hereditary factors that can not be prevented.
When reading, writing or working with a computer, it is advisable to look for distant objects for 5-10 minutes in order to rest on the hearing aid of the eye, especially for children and students.
Treatment of myopia
The correction of farsightedness is done with diffuse / – / glasses or contact lenses. In this way, the problem is almost always fully corrected. In this way the light is broken so that the examined image falls on the retina.
It is possible that myopia is corrected by eye surgery. The most popular procedures are:
Refractive Surgery (Replacement of the Lens with a Cute)
Refractive corneal laser correction. Not everyone can be a candidate for surgical treatment – one has to meet certain requirements that need to be clarified by the treating physician. The long-term effects of laser operations are still unknown.
Our opinion is to resort to surgical intervention only when wearing glasses or lenses is impossible or contra-indicated.
When to look for an ophthalmologist?
Contact an ophthalmologist if your image is blurred, or it is cloudy, blurry, blurred when viewing distant objects if it interferes with your work, school activity or driving.