My doctor asked me to sit on a chair. And then she moved a machine which was placed right in front of me. She asked me to place my chin on a support that was in front of the machine. Then she placed the machine right in front of my right eye. I heard a click. Then she told me not to move my head so she could check the other eye. After this, she asked me to wear a pair of strange glasses and told her the directions of the letters on the wall with one eye. And if i told her that i couldn't see it clearly, she would change lenses. After doing this with both eyes, she told me the degrees of my eyes.