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Visual defects, defects of vision.

Eye without visual defects can form on the retina the image of an object at infinity and is said to emmetropic. This capacity depends on the perfection of the lens of the eye (cornea and lens), which serve to converge the light rays on the focal point. If this point lies in front of or behind the retina images are blurred and it becomes necessary optical correction. Here then present the first defects of vision.
Visual defects (or AMETROPIA) are correctable with lenses:
MYOPIA, ASTIGMATISM, HYPEROPIA, PRESBYOPIA.

Myopia, astigmatism, hyperopia

in Italy of 60 million inhabitants, some 20 million are wearing glasses and of these 15 million are myopic, astigmatic 2 million and the rest of hyperopia.
Astigmatism and hyperopia are congenital and then you can not do prevention for this visual defects, but for myopia plays a key role inheritance.
This is because in case of myopia, family eye examinations of children should be deferred and subject to the two years already. Check for early myopia, in fact, helps to prevent rapid progression.
Besides taking care of doing well the power feed our children foods rich in vitamin A and E, is essential to the environment in which we read, there must be a good lighting should not tire the eye.

On the research front, right in recent British researchers have identified the gene responsible for the onset of myopia and are trying to develop eye drops to prevent or stop this visual defect.
It would be a sensational discovery which would offer a chance to say goodbye to glasses or contact lenses. The research, which was published in the journal Nature Genetics, was conducted by comparing the DNA of more than 4000 twins.
About 45% had a "gene villain" of myopia and those who had two of them was more prone to myopia. To develop a drug that can act on this gene (RasGRF1) must wait at least another ten years.

PRESBYOPIA

Is an inevitable fate for all. The eye can easily see objects at different distances because it has a mechanism (the accommodation of the lens) that allows you to easily move the focus on objects far and near.
With advancing age, and this ability is not a progressive distancing of the object is required to have a clear vision: this is presbyopia.
In subjects with no visual defects this phenomenon appears at around 45, some years before in hypermetropia, myopia in a few years later.
Presbyopia is easily corrected with glasses that make it possible to compensate for accommodative function of the lens: the first will be mild, but every 3-5 years is necessary to increase the power of the lenses until, around 60 years, there is some stabilization.
If you want you can also opt for multifocal contact lenses, which, however, are not the ideal solution because it offers the visual quality is often not optimal. In addition, the lenses require maintenance that is rather laborious and may discourage.

CATARACT

It is not a disease but a physiological phenomenon related to age at all, just like the wrinkles and hairs. A 70 years 3 of 4 people opacity of the lens.
Those most at risk are diabetics, those with a high myopia and those on steroid therapy.
Beware though, the alarm bells: when writing on television no longer appear when you feel discomfort or sharp passing, for example, from the darkness of a tunnel to sunlight, then the case is to be checked because they could all be signs a possible alteration of the lens.
The only treatment is surgery, which has the highest percentage of success among all interventions. In Italy, cataract surgeries each year about half a million people who are able to recover a good view.
Prevention always passes through a careful defense of the eyes from UV rays, but often the elders refuse to bring sunglasses.

Glaucoma

Is the second leading cause of blindness in the world and if untreated leads inevitably to loss of vision.
In Italy there are about 550,000 patients are detected. Its incidence rises to 10% dellla population over 75 years.
The term Glaucoma comprises a heterogeneous group of progressive optic nerve disease in which intraocular pressure is too high, damaging the optic nerve and reduces the visual field.
A fundamental characteristic of this disease is being virtually asymptomatic until the late stages, and although the damage to the optic nerve is preventable, once this is established there is no possibility of functional recovery.
So the only way to intervene in time is to perform periodic check-ups by your eye as early as age 40 with the measurement of eye pressure.
Being a family is very important to control the disease of the patient's family because they have a four times more likely to develop the disease.
In addition, there is a correlation with conditions such as hypertension, hypotension, myopia, migraine, previous ocular trauma, prolonged use of steroids.

SENILE MACULAR DEGENERATION

More than three out of ten Italians, after 75 years, is having to deal with age-related macular degeneration (ARMD in code, age-related macular degeneration). But the disease, which according to OMS is the leading cause of blindness in the Western world, begins to affect between 50 and 60 years. In Italy, in fact, about half a million people in this age group suffers.
The AMD can occur in two forms: dry (or atrophic) and wet (or exudative).
The first gives a progressive thinning of the central retina atrophy of capillaries: a scar is formed with a typical aspect "map.
The second is complicated by the neo-formation of abnormal capillaries, which can cause bleeding.
As with most eye diseases, even in the case of AMD, protection from UV rays with the slow flow rates from childhood and a correct lifestyle are the cornerstones of prevention.
On the front of the laser therapies, today is carried out successfully with verteporfin photodynamic therapy (PDT), which allows it to act even in the most difficult intravenous injection with a photosensitive drug, verteporfin.

DISORDERS "OUTSIDE" (chalazion and pink eye)

The chalazion occurs when a clogged gland which produces tears. When this occurs it forms a plug that inflates the gland and, therefore, the eyelid.
The chalazion resolves spontaneously in most cases. To improve the swelling is useful to apply, for about a week, an antibiotic ointment and a mild anti-inflammatory. Apply warm compresses are also useful for water that encourage the dissolution of the block glandular.
Unlike calzaio, the stye is painful, and it manifests itself like a pimple that appears on an eyelid. Initially the area is red, then more and more swollen until it appears the classic white dot. The person may also have watery eyes and sensitivity to light (photophobia).
The stye tends to disappear within two to three days, the time required for the pus to escape. To speed up the process can be useful to apply an antibiotic ointment (not drops, because they quickly slip away from the eyelid without being able to improve the situation). Doing warm compresses on the area, not only can ease the discomfort, but this way you can also expedite the process suppurative and thus to the "burst" dell'orzaiolo. It 'a good idea not "torturing" the sty, trying to release pus not to further irritate the area.

CONJUNCTIVITIS AND DRY EYE

There is a bacterial conjunctivitis with swollen eyes and loss of yellowish liquid. It is transmitted like a cold or flu. It 'an acute episode that resolves with antibiotic therapy. To prevent conjunctivitis just need a bit of attention to hygiene especially if your family has someone who is suffering from the disorder. So, do not use the same towels and the same pillow and wash your hands before touching your eyes.
More and more widespread then it is the dry eye syndrome. Our tears are responsible for maintaining the humidity of the eye and act as lubricants. Those most at risk are those with systemic diseases (such as Sjogren's syndrome) or autoimmune thyroid disease. Even women who are entering menopause can suffer from dry eye due to hormonal changes that also impact the quantity and quality of tears.
When the problem occurs, it usually uses lubricants such as artificial tears. Because they are truly effective, must be made several times throughout the day to keep the eye moist and treatment should always be ongoing.

SCHEDULE OF VISITS

The first visit is done in the hospital at the time of birth to verify there are no congenital problems. Subsequently, the control should be done at about 3 years to detect any visual defects, which can be quickly corrected with lenses.
The second visit should be provided for school age, to verify the onset of myopia, hyperopia and astigmatism that may affect the proper school behavior and learning.
Another check should be done between 10 and 15 years because this is the age group where 70% of cases occur myopia. As adults, an appointment is required for all of 45 years to see if there is presbyopia, the inability to see well up close. This is also the age at which check if there is any glaucoma in early stage and to verify the conditions of the retina.
Family members of patients with hypertension and diabetes should pay more attention, because it increases the risk of glaucoma and retinopathy. For them, the ophthalmologist will decide, after an initial assessment, the best intervals for controls.
For healthy subjects, the other essential step is located at 65. At this age, we must examine the eye to catch any early signs of macular degeneration in order to intervene as soon as possible.
From that date onwards, if the problems are absent, these checks should be repeated every year because the "sight machine" has done a lot of miles.

EXERCISES FOR THE EYES

On the effectiveness of exercise for eyes there is no agreement among ophthalmologists that, in most cases, considered useless. All, however, agree on the need to take breaks when working on the computer and read a long time to give your eyes time to relax and oxygenate.
Among the exercises that give more relief and can be practiced anywhere, there is the rotation of the eyes. You have to sit in a comfortable position and start rotating the eyes in a clockwise direction. This will flex the muscles that control movement of the external eye. The exercise is repeated in a counterclockwise couple of times, but easy on the eyes. At the end, a massage really helps to relax the eyes and gives a pleasant feeling of well being. Just put your hands over your closed eyes bent without putting pressure on the orbits. At this point, gently massage in circular movements with his eyes slightly and pressing the palm of your hand for about 20 seconds.

DIET FOR THE EYES

The diet that is good to the eye is of colors: pumpkin, oranges, strawberries, raspberries, blueberries, carrots. All fruits and vegetables that contain color pigments are consumed regularly because the color indicates the presence of substances good for the eyes.
We should bring to the table every day (and not just occasionally) foods that contain vitamin E, A and C, but also substances such as astaxanthin, beta-carotene and anthocyanins. The latter belong to the family of bioflavonoids and are found in blueberries, the berries and all vegetables such as cabbage purple color red. As the rhythms of our days we often prevent a bring to the table every day fruits and vegetables, sometimes it may be necessary to use vitamin supplements. It is enough to make two cycles per year for a couple of months, but without neglecting the power which must remain the primary source of prevention.
The supplements are especially useful for children who do not like vegetables and for older people who eat little and badly, and that all the nutrients they need in order to prevent maculopathy.
Recently, an American study, the AREDS showed Casiglio the effectiveness of antioxidants in delaying the onset of the disease. The obligatory with vitamins A, C, E and mineral supplements such as zinc, selenium, lutein. zeaxanthin, astanzantina vote is planned in case of deficiencies found and the conditions of malnutrition or malabsorption.