The light is focused in front of the retina, causing images of distant objects to appear blurry. The normal eye is a perfect sphere, where the cornea and lens focus light to form an image on the back inside surface of the eye, known as the retina. With farsightedness, the cornea's curvature is flat for the shape of the eye. The light is focused in back of the retina, causing a blurred image. The front of the astigmatic eye has an irregular shape, more oval, like a football.
Incoming light focuses at multiple points instead of one.
Astigmatism can make wearing contact lenses difficult or even impossible. Laser vision correction is now an option for people with astigmatism who want clear, comfortable vision. RK stands for Photorefractive Keratectomy, the medical name for the laser vision procedure. You may have also heard about the surgery known as RK-Radial Keratotomy. PRK is not RK, they are two completely different procedures.