Astigmatism is a common condition where fails to focus uniformly on the retina. This uneven focus causes blurred or distorted vision at all distances. It occurs as a result of the curvature in the lens or when the cornea is not shaped as it should be. Astigmatism may occur with two other similar refractive error conditions; myopia and hyperopia.
An irregularly shaped cornea or lens will prevent light from focusing correctly on the retina. The vision then becomes blurred or distorted at any distance. A normal eyeball is supposed to take the shape of a round ball, not a football. A diopter (a unit of measurement of the refractive power of a lens) measures astigmatism. A measurement of 1.5 or more means the individual needs glasses or lenses for clear vision. The average diopters measurement in most people ranges from 0.5 to 0.75.
- Regular: The cornea is curved more in one direction than the other.
- Irregular: The curvature of the cornea is not even.
Signs & Symptoms
- Strain in the eye
- A distorted or blurry vision
- Discomfort in the eye