The test for astigmatism: how to check their own eyes
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 astigmatism at
astigmatism - 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 generated a lot 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.
simultaneously broken 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 - smaller.
you did not notice or experience a few blurred vision.Sometimes uncorrected astigmatism can cause frequent headaches or eye fatigue when visual load.
Astigmatism test - what is it?
All 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.
simple test for astigmatism can be done by yourself.To do this, gently draw on paper with the same lattice of 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 this test astigmatism Astigmatism - lenses, glasses or surgery? 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 radiant figure, for example, Siemens star:
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 picture becomes 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 vision is normal, not unusual for a star of Siemens people will not see.But if you come as close to the image, you can get the same effect.
How to test for astigmatism
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 the Siemens stars.Then check out the other eye, and also check all that you saw.
with normal vision eye clearly sees the same black line without merging to the center.In astigmatism can see the above 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? .
If astigmatism is set and checking the 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.
astigmatism test allows a person to check their own vision, and then decide if it needs to contact an ophthalmologist.