This can include emergency room treatment, as well as treatment by a medical physician or eyecare provider. This page shows simulations of visual symptoms caused by a variety of eye disorders, from refractive error to localized eye problems to neurological problems. Double Vision Color Blindness Ophthalmic Migraine Please note that these simulations are generally based on the author's interpretation of symptoms described by patients, as well as on knowledge of the disease processes themselves. There may be wide variations in an individual's own visual experiences with any disease process. Refractive Errors Refractive errors are optical abnormalities in the eye that lead to improper focusing of images onto the retina.
Refractive errors are generally correctable by glasses, contact lenses, or refractive surgery.
For more information on the optics of the eye and refractive error, go to Optics and Refractive Error. Both the foreground and the far distance are clear. Both distance and near are blurred, but the distance is relatively clear compared to the foreground. Astigmatism Astigmatism is usually caused by the cornea not being perfectly round in all directions, leading to different parts of an image being blurred, depending upon the orientation of the astigmatism. In this image of Capitol Square in Richmond, Virginia, the astigmatism is oriented vertically, thus there is selective blurring of vertical lines as shown in the photo.