Astigmatism is a imperfection in the curvature of the cornea or lens Of the eye. To understand astigmatism, it is useful to imagine that the normal eye is a perfectly rounded ball.
An eye with Astigmatism is not a perfectly rounded sphere, the eye can be egg-shaped or oval.
To define, there are two basic types of astigmatism:
- Horizontal astigmatism: It is when the eye is wider than tall.
- Vertical astigmatism: This is when the eye is taller than wide .
With any of these types of astigmatism, near and distance vision is blurred due to the irregular shape of the eye.
What are the causes of Astigmatism?
Astigmatism is due to the cornea or lens having a different shape than normal. It is a very common visual condition and the exact reason why the shape of the cornea or lens varies from person to person is unknown. But it is known that there is a hereditary risk factor that is passed from parents to children.
Other causes:
- eye disease
- Eye trauma or injury
- After some eye surgical procedures.
In common language it is said that astigmatism can appear or worsen from reading in low light or from sitting too close to the television, this is FALSE.
How does astigmatism affect vision?
When there is astigmatism, it happens that the light rays entering the eye are not refracted correctly, forming distorted images before the foveal point of the Retina or in the posterior part of it. It is very common for Astigmatism to occur associated with other refractive errors, such as:
How do you know if you have astigmatism?
Symptoms of astigmatism may include the following:
- Blurred vision or areas of distorted vision;
- Eyestrain;
- Headache;
- Squint your eyes to see more clearly.