MAJOR PROBLEMS VISUALS
MAJOR PROBLEMS VISUALS
In order to be able to see or, it is needed that the images arrive clear and correctly to the brain so that can identify them and process, when this happens, says that the eyes are
when the images do not arrive from clear form because the light rays arrive at
center or place from the inadequate eye, take place distortions that
on the ocular
and to this abnormal eye is denominated to him or amétrope.
. One appears when the light rays focus not directly in front of the
and on her, causing who the near objects are seen easily,
the distant ones are difficult to distinguish. This
deformation of the ocular globe, that appears extended or because the crystalline
smaller focal length to the
one and it is corrected with concave lenses that extend the focal length or with refracting surgery.
Hipermetropía, when the light rays project the image in
point behind the
, causing that the near objects are blurred. This
is caused by
or crystalline with little curvature or because the anteroposterior axis of the eye is shorter. One is made up with convex lenses that are heavier in the center that in the edges and shortens the focal length or with refracting surgery.
Astigmatism, happens when there is
deformation in several parts of the
, the membrane is transparent that it covers to the eye, causing that does not form
center on the
generally incomplete or distorted confused image. The lenses that correct this
are the cylindrical ones, that channels light rays towards
unique focal point. Also it is corrected with refracting surgery. This
causes pains in the eyes and head and much eye
that affect the vision are:
Presbiopía or presbicia. Also it is known him as "tired Vista" and is developed with the age. It is caused by the hardening of the crystallines, that lose something of elasticity. One generally begins to declare as of the 40 years and the person who suffers it must move away the small objects to be able to see them with clarity. She corrects herself with
to see close by and / or different graduation in
eye, that she must
regularly until more or less the 65 years of age, when the
generally no longer increases.
Color blindness or blindness to the colors, is
suffering that it prevents to the cones of the
to distinguish all the colors or certain tones of color. The majority does not distinguish between the
one and green and the others cannot do it between tones of blue and
. Although it does not have cures for this
, if the
worsens, are possible to be suggested dyed
to distinguish between the colors that are confused.
Ambliopía, also well - known like "syndrome of the sluggish eye or vague eye", is the partial loss of the vision of an eye. In rare occasions this
can be presented / displayed both in eyes, with very clear signs of tremor or involuntary ocular movements.
It is caused mainly by the presence of estrabismo and the fixation of "the normal" eye. Another cause can be anisometropía, or difference of graduation from an eye to another one, which causes
delay of the
capacity of the defective eye. Also it is caused by
Better well - known like "cross - eyed eyes". This suffering is characterized by the loss of the parallelism of the eyes, is to say that while one of the eyes watches an object, the other turns aside in another direction causing in many cases
showy aesthetic defect. This must to the alteration of muscles of the united eye to
bad vision mainly, that is to say, an eye is turned because it sees bad and sees bad because it is turned. The
is corrected by means of the use of lenses with special crystals, the occlusion of the eye turned aside with patches,
exercises and in some things by means of surgery.