Astigmatism usually takes place when the front surface of the eye, the cornea, has a curvature that is uneven. A group of eye conditions referred to as refractive errors is linked to astigmatism. Refractive errors lead to a malady in the manner that light rays are focused inside the eye. Astigmatism is normally associated with nearsightedness as well as farsightedness. They are conditions that can be recognized as refractive errors. Astigmatism is not an ailment, nor does it signify that a person having it has bad eyes. It merely implies that a person has an alteration or blemish in the shape of the cornea.
Causes of Astigmatism
- Astigmatism normally takes place when the cornea which is the front surface of the eye, has a curvature that is uneven.
- Commonly, the cornea is even and uniformly curved in all directions enabling the light going to the cornea to be focused in an uniform manner on all planes, or in all directions.
- When the front surface of the cornea is curved exceptionally in one direction in comparison to the other, it gives rise to astigmatism.
- This flaw may give rise to a vision that is akin to looking at a hazy, undulating mirror.
- The aberration results due to the failure of the eye to focus light rays to a point.
If the corneal surface is marked by an extraordinary degree of disparity in its curvature, light refraction may be weakened. In that case, corrective lenses will be required to assist in focusing light rays in a better manner. At all times, only a minor quantity of the rays are focused and the rest are not; so that the image that is created, is always hazy. Normally, astigmatism results in hazy eyesight for all distances. Certain individuals with very high levels of astigmatism may have complications with the cornea – for instance, keratoconus.
Astigmatism is very widespread. Some experts are of the view that nearly everyone has astigmatism to some extent. The condition may arise right from birth and continue throughout life. The precise reason for dissimilarities in corneal shape is yet to be ascertained. But, the inclination to develop astigmatism is hereditary. For that reason, certain individuals are more prone to develop astigmatism in comparison to others.
Symptoms include distortion or haziness of images irrespective of the distance, headache and exhaustion, squinting and discomfort in the eye or pain.
- In cases of astigmatism that is minor in nature and without any other complications associated with refraction, for instance nearsightedness or farsightedness, corrective lenses may not be essential.
- If the extent of astigmatism is major enough to result in eyestrain, headache, or haziness of vision, prescription lenses will be required for alleviating the problem.
- The corrective lenses necessary to deal with problems associated with astigmatism are known as Toric lenses and possess an extra power element called a cylinder. They have better light-bending capacity in one axis than in others.
To learn more about the condition of astigmatism, please read our related article Astigmatism Test