What is the Meaning of refraction | Definition and Concepts
The vices of refraction are a set of disorders of vision that originate difficulty to see objects, depending on the cause that produces them can be of three types including myopia, hyperopia, and astigmatism.
In the body this same phenomenon occurs when light passes from air to the eye through the cornea and lens. At this time the light rays change direction in order to be focused on the retina to see a particular object of sharp and clear way.
In some circumstances the refraction of the light originates distorted or blurry images which gives rise to three disorders of vision which are known as vices of refraction.
Myopia. In this disorder the images form ahead of the retina since the eyeball has a length greater than normal anteroposterior, its main manifestation is the difficulty in clearly see objects that are far away.
Hyperopia. In this case the images are formed behind the retina, contrary to what happens with myopia eye is shorter than normal which leads to that occurs a difficulty for near vision, while distant objects can be clearly seen.
Astigmatism. In this condition the problem lies in the cornea occur when this rather than being spherical shaped flattened at the ends which makes light to sustain the process of refraction at different angles which makes that objects are perceived in distorted form. Astigmatism affects both near vision as near-sightedness and may occur alone or in combination with myopia or hyperopia.
It is also possible to carry out the correction of these problems through surgery with x-ray laser, changing the surface of the cornea in order to turn it into a lens, thus solving the problem.
What is refraction?
Refraction is a phenomenon that occurs when the light in its way must go through media with different densities, the classic example is placing an object inside a glass of water and see how it gives the impression that it is folded. This is due to the fact that moving to a more dense medium light is forced to divert its route.In the body this same phenomenon occurs when light passes from air to the eye through the cornea and lens. At this time the light rays change direction in order to be focused on the retina to see a particular object of sharp and clear way.
In some circumstances the refraction of the light originates distorted or blurry images which gives rise to three disorders of vision which are known as vices of refraction.
Main defects of refraction
Depending on the effect that occurs in the way how the vision takes place the vices of refraction are classified into three main types.Myopia. In this disorder the images form ahead of the retina since the eyeball has a length greater than normal anteroposterior, its main manifestation is the difficulty in clearly see objects that are far away.
Hyperopia. In this case the images are formed behind the retina, contrary to what happens with myopia eye is shorter than normal which leads to that occurs a difficulty for near vision, while distant objects can be clearly seen.
Astigmatism. In this condition the problem lies in the cornea occur when this rather than being spherical shaped flattened at the ends which makes light to sustain the process of refraction at different angles which makes that objects are perceived in distorted form. Astigmatism affects both near vision as near-sightedness and may occur alone or in combination with myopia or hyperopia.
The refractive defects are corrected by adapting corrective glasses or lenses
The ophthalmologist can determine whether or not it exists a vice of refraction and even measure its magnitude, due to possible adapting corrective lenses that allow correcting the angle with which refracts light in eye obtaining thus a sharp and clear view of objects.It is also possible to carry out the correction of these problems through surgery with x-ray laser, changing the surface of the cornea in order to turn it into a lens, thus solving the problem.