Related articles: Astigmatism
Definition
Astigmatism is a refractive defect caused by the asymmetric (not spherical) curvature of the cornea or crystalline lens. This anomaly causes light rays of different orientation (eg oblique, horizontal or vertical) to be focused at different points of the retina. In other words, the astigmatic eye focuses light stimuli correctly only along an axis, so objects both near and far are poorly defined or distorted.
Astigmatism can occur along with myopia, hypermetropia and presbyopia.
Most common symptoms and signs *
- Eye fatigue
- Burning eyes
- Ocular pain
- Tearing
- Headache
- Misaligned eyes
- Reduced vision
- Double vision
- Blurred vision
Further indications
Astigmatism results in less visual clarity and the images are blurred. The defect is present by looking at it from afar, or closely. The symptoms associated with astigmatism consist of pain in the eyeballs, headache, burning eyes, excessive tearing and feeling of fatigue. These are disorders that occur mainly after prolonged visual effort.
Astigmatism can be easily identified thanks to an eye examination. To correct this visual defect, glasses with cylindrical or toric lenses, or gas-permeable or soft contact lenses are used. These lenses do not have refractive power along an axis and are concave or convex along the other. Surgery is also an option available to correct astigmatism.
