The test for astigmatism: how to test your own vision

October 23, 2013

 test for astigmatism
 The test for astigmatism can be done at home, without leaving your computer. However, many people who believe their vision is normal, was surprised to find that they have symptoms of astigmatism. There is nothing surprising in this - a small astigmatism phenomenon many people have, but that does not prevent them from having good vision.


What are the characteristics of at astigmatism

Astigmatism - is a violation of the refractive power of the cornea or lens. More common congenital corneal astigmatism, which develops due to the fact that the cornea is not spherical but dyneobraznuyu form, that is, has different curvatures in different directions. As a result, the cornea refracts light in the wrong, and instead of a focus on the retina is formed set of tricks, some of which are located on the retina (emmetropia), as part of the front (of opium) or (hyperopia) retina.

Due to the large number of tricks a person suffering from astigmatism, sees everything vague. Straight lines often appear to him in waves, identical in thickness and line color - different. He can not understand what is the closest thing to it, and some more.

At the same time disturbed and visual acuity: astigmatism can be myopic (nearsighted) and hyperopic (farsighted). When reading a book or checking visual acuity at special tables for blurring of the patient may not be called large letters, and clearly - more than fine.

You can not ignore it or to experience a few blurred vision. Sometimes uncorrected astigmatism can cause frequent headaches and eye fatigue when visual load.


Astigmatism test - what is it?

All the features of astigmatism when used in special tests for the detection of this pathology. Minor (up to 0.5 D) the degree of astigmatism usually do not cause visual impairment, but passing the test you will notice its presence. In this case you should consult a doctor to make sure that the correction is not required.

The simplest test for astigmatism can be done by yourself. To do this, gently draw a grid on the paper with the same along the length, thickness and degree of coloring lines and start to rotate it in front of his eyes. In normal vision grille will always look the same when it astigmatism lines will appear to the flat, the uneven thickness of the lines and the color intensity also will appear the same, it is uneven. This occurs because the incorrect curvature of the cornea leads to a distinct focus on certain parts of the image and blur the rest.

With such a test astigmatism Astigmatism - lenses, glasses or surgery?  Astigmatism - lenses, glasses or surgery?
   You can determine whether the curvature of the cornea or lens is correct.


What are some other tests for astigmatism

They set. The most commonly used rayed shape, for example, Siemens Star:

 test for astigmatism

In this picture, the black rays on a white background rush from the periphery to the center. If you have astigmatism, the rays do not reach the center, begin to merge with each other and with the surrounding background. Then, as further progress towards the center of the rays again are clearly visible, but the image is converted as if in a negative (black rays become white and vice versa). Different people with astigmatism may see a different number of such changes.

If the vision is normal, not unusual for Siemens Star people will not see. But if you come as close to the image, you can get the same effect.


How to test for astigmatism

To test for astigmatism is very simple. We need to sit up, there is an image of the test in line with the eyes at a distance of 35 cm from them. Close one eye and look closely at all the features of Siemens Star. Then check out the other eye, and also check all that you saw.

In normal vision, the eye clearly sees the same black line without merging to the center. In astigmatism, you can see the above-described phenomenon.

But this is not end of the world, it is possible that the doctor will change the minimum and deems them are normal. If it turns out that the astigmatism still affect vision, you will just spend it corrected with glasses or contact lenses Contact lenses - whether they can completely replace the glasses?  Contact lenses - whether they can completely replace the glasses?

When astigmatism is set, and verification of visual acuity. Because of the fuzzy focus large objects (eg large letters on the table for testing visual acuity) will look unclear and people with astigmatism often wrong, calling them. A smaller letters he can see clearly and correctly called.

The test for astigmatism allows the person to check out your own eyes, and then decide if it needs to contact an ophthalmologist.

Galina Romanenko

Article Tags:
  • astigmatism

Symptoms of glaucoma - it is important to notice in time

September 29, 2013

 Symptoms of glaucoma
 Symptoms of glaucoma - it increased intraocular pressure, squeezing, and degenerative changes in the optic nerve and gradual loss of vision. Unfortunately, not always all of these symptoms are detected in time, resulting in developing irreversible visual impairment and sometimes blindness.

 Symptoms of glaucoma - it is important to notice in time

Main forms and stages of glaucoma

There are three main forms of glaucoma: open-zakratougolnaya and mixed. In turn, each of these forms is separated into stages:

  • Stage I - Primary
  • Stage II - developed
  • Stage III - advanced stage
  • Stage IV - terminal

The dynamics of visual functions at the same time assessed as stable (decline of stopped) or unstabilized (fall of proceeds).

When closed-form aqueous humor in the anterior chamber of the eye builds up due to the fact that the iris covers the angle of the anterior chamber of the eye - is blocking access to the fluid outflow pathways. Open-shape characterized by the fact that changes occur in the system of aqueous humor outflow. When mixed form of glaucoma in one way or another, both mechanisms are involved violations of the outflow of fluid. Sometimes developing glaucoma with normal intraocular pressure - changes in the optic nerve at the same time are due to circulatory disorders.

Symptoms of glaucoma eye depend on the mechanism of the disease.

 Symptoms of glaucoma - it is important to notice in time

Symptoms of open-angle glaucoma

Open-angle glaucoma is usually simple and consistent signs of congestive glaucoma. Simple glaucoma is characterized by three main symptoms: increased intraocular pressure, reduction of (primarily due to the narrowing of the visual field) and excavation (recess, indentation) of the optic nerve. The second and third are the consequence of the first symptom, therefore develop later.

Simple glaucoma progresses and begins quietly with the changes of the peripheral visual field (narrowing it to the side of the nose). Later begins to suffer and central vision. Over time, there is only light perception, and then complete loss of visual function. Visual disturbances in simple glaucoma develop so quickly, that the patient may not notice them even blindness in one eye.

When running a simple glaucoma when visual function is already lost, in the foreground can be a pain - is developing so-called absolute aching glaucoma Glaucoma - a perspective possible blindness  Glaucoma - a perspective possible blindness
   - There are constant headaches and pain in the brow area.

In congestive glaucoma occur all of the above changes, as well as well as changes in the anterior segment of the eye anterior chamber becomes shallow, the cornea swells, its sensitivity decreases, blood vessels in the area overflowing with blood, the pupil dilates. All this leads to periodic blurred vision, the appearance of bright circles around lights, moderate pain in the eye and temple, the fall of dusk.

Open-angle glaucoma usually occurs on both sides, but takes on different eyes are not the same, with varying degrees of decline.

 Symptoms of glaucoma - it is important to notice in time

Symptoms of angle-closure glaucoma

Angle-closure glaucoma is less common than open-and usually occurs as acute attacks of glaucoma. Acute glaucoma attacks can be triggered by stress, dilated pupils (for example, when taking certain medications, instillation of eye drops, contributing to the expansion of pupils stay in the dark).

Intraocular pressure thus rises to very high numbers (sometimes to 80 mm Hg). Seeing drops sharply, sometimes after an acute attack of glaucoma comes complete irreversible blindness. Reddened eye, shallow anterior chamber or missing entirely, pupil enlargement, has the shape of a vertically elongated oval. Pain in the eye, and headache Headache: Causes and Complications  Headache: Causes and Complications
   It may be so strong that they can not be removed even with narcotic analgesics.

Often during an attack of pain there are such vegetative effects such as nausea Nausea - there may be problems with the nervous system  Nausea - there may be problems with the nervous system
 , Vomiting, dizziness, Dizziness - if the ground is slipping from under his feet  Dizziness - if the ground is slipping from under his feet
 . Pulse is a rare, pain may be of the nature of the reflected and manifested in the form of pain in other organs, such as in the heart or the stomach.

Transferred acute glaucoma attack leaves atrophic foci (areas of destroyed cells) in the iris, sometimes - a persistent mydriasis, cataract and so on.

An acute attack of glaucoma requires emergency medical care. As a rule, such assistance is provided in a hospital environment. If timely assistance is delayed, then the outcome of the attack could be blindness.

Glaucoma - a disease that requires timely detection and adequate long-term treatment.

Galina Romanenko

Article Tags:
  • glaucoma