|
Astigmatism is an eye condition which can cause blurred vision, headaches and fatigue. However, the right glasses or contact lenses can usually correct the problem.
If the curve of the front surface of the cornea, the outer covering of the eye is irregular, the person will see a distorted image. This particular kind of defect is called Astigmatism.
In fact, nearly everyone's eyes are affected to some degree by astigmatism, because very rarely does the front surface of the cornea provide a perfect lens. If the irregularity is slight, vision will not be noticeably affected. If it is marked , however, the image will be distorted- with vertical, horizonal, or diagonal blurring, depending on the nature of the imperfection and the condition will require treatment.
Astigmatism may be present at birth or it may develop in childhood over a number of years. Severe astigmatism may be inherited. Sometimes it is secondary to other eye conditions or it can be the result from the formation of scar tissue after the cornea has been diseased or injured. Or it may follow eye operations such as the removal of cataracts.
Astigmatism should be suspected in someone who narrows their eyelids to a squint to see clearly. Diagnosis requires careful assessment of the irregularities of the cornea, testing with special patterns to determine exactly which part of the image is distorted and how severely.
Astigmatism is harder to correct than straight forward long or short sight. The most common way is to prescribe glasses with cylindrical lenses ground to the required curvature, though the wearer may still notice some blurring. If astigmatism is accompanied by short or long sight, compound spectacle lenses are the answer. Contact lenses may also be used and very severe cases may need a corneal graft.
| 
