Dishler Laser - Blog

We talk about astigmatism in abstract terms but seeing it graphically can help to visualize exactly what the problem is and how it can best be corrected. Here we see the actual astigmatism of a real patient which is fairly extreme being over 6 Diopters in amount. What this means is that the cornea is shaped like a football on the front surface, and therefore light rays are focused differently depending on their orientation. This output is from an actual patient we recently treated at our office who is a pilot and depends on clear vision for his job and safety. The 3-D map is created by a device called a Zywave. It works by sending in straight rays of light into the eye and looking at how they are distorted as they travel through the eye, essentially a reflection of the red eye that is seen in photographs of the pupil. Here we can see that there is a significant distortion of the light caused by the irregular shape as seen at the bottom of the cube. The LASIK procedure can reshape the eye, resulting in much lessened distortion of the light and a flattening out of the shape seen in this image. When the shape is flat and in the correct plane this corresponds to sharp clear vision as was exhibited by this patient after his LASIK procedure was completed. Click on the title to see the image discussed above.