Astigmatism
If you experience a distortion or blurring of images at all distances -- nearby as well as far -- you may have astigmatism. Even if your vision is fairly sharp, headache, fatigue, squinting and eye discomfort or irritation may indicate a slight degree of astigmatism. A thorough eye examination, including tests of near vision, distant vision and vision clarity, can determine if astigmatism is present. Astigmatism is not a disease nor does it mean you have "bad eyes." It simply means that you have a variation or disturbance in the shape of your cornea.
Astigmatism is one of a group of eye conditions known as refractive errors. Refractive errors cause a disturbance in the way that light rays are focused within the eye. Astigmatism often occurs with nearsightedness and farsightedness, conditions also resulting from refractive errors.
In a normal eye, the cornea and lens focus light rays on the retina. In astigmatism, the cornea is uneven. Images focus in front of and beyond the retina, causing both close and distant objects to appear blurry.
Examples of Astigmatism
As the photos below illustrate, with astigmatism, images can appear elongated.
