Astigmatism is an eye disorder which is caused due to irregular cornea or lens, causing the image to be out of focus, producing faulty vision. It is corrected by cylindrical lenses.
The condition causes blurred vision, headaches and fatigue.
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, horizontal, 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.
The person suffering from Astigmatism usually 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 can be corrected by using 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, wearer should choose compound spectacle lenses.