What does farsightedness depend on?

Farsightedness  is a visual defect often due to a shorter eyeball .The consequence is that images are focused over the retina.

Generally is an innate defect ,but it appears mostly with aging.

When eyeball is shorter, images are focused behind retina.

You born farsighted, but, in most of the cases you find out hat you are only when you are over with the years. Many people apparently devoid of visula defects are, in fact, light farsighteds- says Paolo Nucci, director of Unversity Opthalmology Clinic of san Giuseppe Hospita in Milan  and president of  pediatric Opthalmology Society -. Farsightedness is refractive defect (as shortsightedness and  astigmatism) linked to a shorter eyeball:this matter brings the images to be focused behind retina.

Why do we not recognize farsightedness ?

Farsighted eye,above all in medium-light type, has the capacity of correction of defect through accommodation, in other words the power of focusing that crystalline has.This skill is at its highest in chilndren and gets lower with passing of the years, so, farsightedness  gradually tends to be no more balanced and so, to request a correction. usually the correction is necessary at a young age in presence of serious and non balanced kinds.

What are the consequences of farsightedness?

Usually farsightedness has not the tendency of progression, on the contrary in some cases with development of visual apparatus it can decrease ,because eyeball assumes a longer shape. But, as for the kids an high farsightedness implies the risk of amblyopia ( lazy eye)  and a tendency to  converging strabism. the first it develops, for exaplme, when in presence of a different farsightedness in the two eyes : the subject can tend to accommodate with the ye that has the minor defect, with the result that brain always receives blurry images to the ey that see less well. Strabism development, instead, is often linked to the fact that the continuos effort of focusing can bring to converge the eyes too much.

So, when do we have to check up the kids? 

For the cited risks, we always recommend an aye check up when they are 3 years old. For diagnosis they use some drops that make the pupil be expanded and that, impeding accommodation, allow to discover farsightedness : light  (from 1 to 2 diopters), medium (from 2 to 4 diopters ) or elevated  (over 4 diopters).

What are the possible signals?

At a young age the light- medium  farsightednesses do not bring generally symptoms ; sometimes there can be a light visual fatiguing due to continuos accommodation effort . The elevated farsightednesses,instead, bring nealy always difficulty in vision both near and far. With passing of years it can, furthermore, happen that a farsightedness that before was converging , begins to appear with foggy vision, reddening and stinging of the eyes, sometimes headache.

How can it be corrected?

Until farsightedness is converging with accommodation there is no need of treatment  but only periodic check ups. When a correction ,you can count on glasses, contact lenses and surgery. The glasses have convergent lenses , to let, as contact lenses, that images fall on retina , not behind. For an elevated farsightedness we can use refractive surgery, if there are indications. The results, in general are reasonable, but they are less predictable than what happens with shortsightedness. There are people who propose ,for elevated disorders, intraocular lenses to be put over the natural crystalline, with the risk of encouraging an opacification of crystalline( cataract) . So, it is better to think about it well, especially when the candidate is young .

Source: Antonella Sparvoli, Corriere della Sera

Read also :

• Prevention is better than a cure
• Are you sure you have the right correction? sight is serious matter
•  Visione as a primal need
• The eye...the older it is, the more attentive becomes!