What is daltonism? History

The daltonism is the inability to perceive certain colors, or in some confusion as red and green. This problem was first described by English chemist John Dalton (1766-1852). This condition is hereditary and is linked to a recessive gene associated with the sex of the person and linked to chromosome X. Since women have two X chromosomes, they may be carriers of the disease, but few have it. By contrast, men usually do.

Moreover, about ten men, one holds a degree from Dalton. A cell is altered, thus directly affects the cone cells of the retina that are responsible for color perception. There are several types of Dalton, among which is the rarest of the monochromatic or cone acromatopsia. This event prevents the detection of colors, so that the person sees in black and white, and that it affects both sexes equally. Dichromate is otherwise for those who possess only two of the three types of cones in the retina.

They are divided into protanopes: Individuals sensitive to red, representing one in every hundred men, deuteranopes: confused shades of red, green and yellow and affects five of every hundred men, and tritanopes: blind to blue and confused shades of green and blue.

What is astigmatism?

It is one of the leading causes of delay in school and should diagnose it in time to avoid other annoyances associated.

Astigmatism occurs when the cornea has an uneven curvature. It can be inherited or acquired (post-surgery), and there isolated or associated with myopia or hyperopia.

Early diagnosis is very important because it will avoid a loss of visual acuity, that in the myopic astigmatism is generally low and reduce the symptoms of visual asthenopia (after reading conjunctival congestion, headaches, poor school performance) and amblyopia (double vision ).

The child must carry with astigmatism lenses cylindrical, using glasses or contact lenses. No surgery is indicated.

How to protect the vision in the work

The visual problems that accompany to the intensive use of the computers, affect many people. The work makes that we fix our look in the screen of the computer during a long time period every day, what tire too much the view.

The immediate consequence is that the eyes begin to dry off, the view you blurred restitution, we suffer headaches and neck, and we are overworked in an immediate way.

When happening ésto, we make an effort in seeing in an excellent way to as we came him making, and for it, we begin to use other muscles of muscles like for example those of the forehead nape and shoulders, causing pressures and subsequently contractures.

For all ésto it is recommended to make a series of small spans amid the labor task, and this way to be able to release the musculature of the eyes of the excesses of pressure, already ea frequently closing them, or covering them with the hands.

Next, we offer you some advice so that you protect your view in front of the screen of the computer.

- You use a glass filter or of plastic of high quality in the computer, to avoid the reflections of the light. Evita those filters carried out with cloth or network.

- You use a lectern to sustain documents or books. Locate it near the screen.

- You locate the screen below about 20 more grades of the level of the eyes.

- The screen should be at a distance from 40 to 75 cm of your eyes.

- Evita the very brilliant light above your head, especially if you are fluorescent.

- You take your look of the screen from 5 to 10 seconds, every 10 minutes.

- The monitors with darker letters on more luminous bottom are much easier of reading.

- The screens of can resolution reduce the visual pressure.

- You darken the room shutdowning some lights or covering the windows with a screen. You locate your work place in right angle with the window that this is not neither you face neither behind the computer.

- You consult with your oculist if you beneficiary to use special glasses for the computer, stiller if you use bifocal.

- Get used to blink followed and regularly.

Bionic vision - artificial eyes

Undelete the view again, you are a very ambitious, more ambitious objective that to undelete any other body organ. To the applicants to develop kind of a bionic eye, they still have left a lot you, and the prostheses to implant electrodes directly in the brain like one makes with other organs, they are also in a very preliminary process.

The scientists got that a person to which were applied this developing treatment as test, saw points called luminous "fosfenos", (the stars that appear when being rubbed the eyes) when they sent you electric stimuli. With signals in sequences that drew forms, that person ended up reading letters. The results of this studio in the visual cortex of a blind person during 22 years, are very esperanzadores to develop a visual prosthesis.

The future objective, logically, consists on connecting a device from these features to a camera, and to a computer able to translate the images. but to marry chips permanently the brain outlines problems of surety. for example, one of the questions vugentes is still that you would happen if the metal of the electrodes, by force of supporting electric downloads, becomes noxious substances for the nerve tissue.

Even this way, you are viable this resource for which still exist a hope to undelete the vision of those non seers.

Retinal Detachment

The retina is the nervous membrane of the eye and the most important. Their intimate structure is not exactly same in its fullest extent. A petty part exists, in what we could name axis central, called stain or yellow blemish that it allows the perfect vision of the objects for its fine composition. Their alteration well for accident or for illness, it determines the visual central forfeiture.

Their lawsuits are numerous, but maybe the most frequent have a vascular origin, be general or local, that is to say reside in the same vessels of the retina or not. It can exist the occlusion of the central artery or a thrombosis of the vein, general ledger haemorrhages or pettier importance, phlebitis, alterations originated by the diabetes, the hypertension, the arteriosclerosis, etc. many times the sick person experiences a visual forfeiture, in a sudden or gradual way, according to the affection that it is. It owes recomendársele that still not being pains, be made recognize urgently for the expert.

The retina can also suffer degenerative, parasitic illnesses, tumors, etc.; that they usually carry always importance.

As it is that the retinal detachment is the most frequent affection and it is usually in the mind of many people, it is considered opportune to extend in the relationship of its lawsuits, symptoms and treatment. A good number of cases can cures with surgical medical treatment and what is more important, to be prevented by means of periodic visits to the expert. The treatments are usually effective and with a good prevention many times the feared abruption doesn't arrive.

Condition such as inflammatory alterations of the ciliary body, processes senile involutivos or degenerative, some vitreous mood disturbances, cranial traumatisms or violent efforts, certain coroides tumors, some possible acarid like the cisticerco and, certainly, the hereditary predisposition, they are lawsuits common of the retinal detachment, as he/she comes off of the test of all the oculists. The most frequent lawsuit that originates the retinal detachment resides in the myopia, visual quite communio bug. Of there the importance that all myopic fellow goes to the specialist physician regularly, not only as soon as it concerns to his optical correction that should be always for that, but also to prevent the possible retinal detachment appearance. The myopia like refractive bug is strange, the so much biggest percent constitutes it the nearsighted illness or myopia axil. All myopic person, although it already takes the appropriate eyeglasses and believe to be well, he/she should go to the oculist at least once a year. Many abruptions and other visual serious dysfunctions would be avoided if you follows this standard and not the pernicious and frequent custom of going to the optics store without the previous visit to the specialist physician.

The sick person at the beginning of the retinal detachment, notes that he lacks a part of its visual field, or you see the deformed objects and it appraises in general kind of a velum or of curtain for before the space that is about looking with one of its eyes. This sensation, days before he/she can go preceded of fotopsias, that is to say, as of some luminous gleams more or less volatile. With the night rest the symptom sometimes disappears, but he/she repeats and it is accentuated as they lapse the hours of the day. The fellow doesn't sometimes perceive these symptoms, mainly if the eye with abruption already had worse vision or knowingly he/she went defectively corrected.
Although in general a retinal detachment doesn't require an operation of urgency, it is convenient that the patient is visited soon. The oculist should make a careful exploration of the bottom of the eye, and overdraft the abruption, although it is of little extension, it will overwork the exploration in the search of some possible retina fissure. It is not always in the first exploration, for what is advisable some days of absolute rest in bed with binocular bandage to discover the fissures before making the intervention, only mean of obtaining the cure of the illness.

The more old it is the abruption minors possibilities he/she offers of a total cure: because although in the surgical aspect the reaplicación of the retina can be procured in its place, the grade of visual recovered capacity is affected by the lapsed time. It is explained to it because, to the being the retina such a delicate membrane, and when being deviant of their free position, it is affected in their nutrition, with the degenerative consequential alterations, accented point as much as general ledger has been the time in that the retina has suffered this deviation.

Cataract Operation of the Eye lens

He is named cataract to the operation of the eye lens, and it in fact consists on extracting it opacificado. Usually, the eye lens has the form of a biconvex lens and a size of 10 millimeters in equatorial sense and 5 millimeters of anteroposterior axis. For the accommodation quality, thanks to some special fibers, it is the one that completes the most important paper because it is the one that decides the focus of the proximate objects.

The lawsuits that can give place to the cataract are multiple. Among them hereditary factors that would determine in the mature or senile age their formation fit. On the other hand, genetic and embryological factors exist, and already in the maternal cloister he/she can the petty one to lose temper, with the following appearance of a congenital cataract that will show in the youth in occasions.

But, there are also general illnesses that can end up manifesting this illness: the diabetes, the intoxications (be due to the naphthalene, to the thallium or the rye ergot), and certain medicinal preparations that are used to cure the obesity and that they contain dinitrofenoles. Those cataracts generally enter a quite quick evolution and their only treatment consists on the operation. Other less frequent lawsuits exist, as a consequence of dysfunctions endocrinológicos pluriglandulares, as gónadas and paratiroides. In the mongolism and the mixedema it is also conserved, in occasions, the appearance of cataracts.

The most usual case is represented by the call senile cataract whose lawsuit is not still known with accuracy, but that it constitutes a positive manifestation of the age. They probably take place in the organism metabolic general dysfunctions that little by little drive to the formation of the cataract. At the beginning they are noted in one or both eyes diverse symptoms, being the main one the visual gradual forfeiture. He suits to keep in mind that simultaneously to the appearance of the cataract, the sick person can it turns affected by other eye diseases that if they are not on time, they would originate complications that can waste or to already make useless the operation of cataracts.

If the patient uses correction, he notes that her glasses don't help him I eat before, you see the deformed images and he searches a luminous more efficient focus, or on the contrary, the (when the opacificación takes place preferably in the center of the eye lens) sick person is better in the dimness, because when dilating the pupil you go with more easiness. At the beginning, it still fits some change in the corrective glasses, but as the cataract, this measure evolves it is useless, the patient loses vision and the best thing is an intervention for the expert.

Conjunctivitis

The conjunctivitis is the inflammation of the conjunctival one whose nature is almost always of extraneous origin, and there are them of diverse classes. They receive the microbial agent's name that produces them and they can be catarrhal, purulentas, membranous, flictenuares, among other. One can suffer in an acute or chronic way, but the exact diagnostic determines it the oculist.

If he/she doesn't get complicated the cornea, the conjunctivitis sick person it notes the appearance of foreign bodies, nuisances to the light or fotofobia, pain, difficulty in the visual effort and fleeting enturbiamiento more or less repeated of the vision, with general ledger or pettier secretion of exudates that can be filiform, serous or purulentos, according to the conjunctivitis class that is suffered. to the awakening, the lids are more or less sticky, edematosos and red. The slot of the lids diminishes of size and the conjunctival tumefacta is observed, red and frequently with petty ecchymosis, that is to say, by way of petty haemorrhages localized in the funds of sack conjuntivales.

For the treatment of these conjunctivitis, diverse collyriums can be used that exist in the market: of astringent type for the filiform secretions, sulfamidados in the serous exudations, and antibiotics in the forms purulentas. Nevertheless, it should be had it enters that of not being appraised an immediate improvement, it is preferable to consult to the expert who will determine the conjunctivitis type and their perfect treatment and cure exactly forthwith.

He/she suits to remember that the conjunctivitis chronicles or not well treated they are much more difficult of curing and they can produce complications in the cornea. In the children, more specifically in the newly born ones, special care should be had, making sure that an obstruction of the channels excretoras doesn't exist. Be like outside, he/she should be treated the conjunctivitis as soon as possible to avoid serious complications in the cornea that you/they can affect in the future to the vision. The conjunctivitis gonocócicas, diftéricas or variolosas, they are extraordinarily serious for who suffers them.

Non debit side to forget the conjunctivitis tracomatosa that although in the last years it has fallen vastly in importance, they continue existing cases in an endemic way, susceptible of infection and of chronic path, as the spring conjunctivitis that charges vigor annually in the station changes.

Finally, he/she suits to keep in mind that the conjunctival one is susceptible of suffering different tumors, benign or malignant, for what you/they should not be neglected never, although they don't produce pains and not even nuisances. It is advisable to consult to the family doctor who will indicate the convenience that he/she sees them the oculist.

A curious formation conjuntival, in general benign that usually leaves of the interior angle of the eye toward the cornea, with trend to cover it, it is the pterygium, called this way by their form and light transmission that make it similar to the wing of an insect. If this pterygium of dilatory path, is progressive, it requires surgical treatment.