Questions about the pupillary distance of the eye

According to your description, your mistake lies in the fact that you are not clear about the actual concept of mm millimeters and cm centimeters, and there is no visual impression of these two units in your mind. You can get a ruler to understand the actual length of mm and cm, after having the most intuitive feeling and impact you will understand why you are wrong. Pupillary distance is the distance between the black eyeballs of your two eyes, and the normal range is between 55 - 65 millimeters which is between 5.5 - 6.5 centimeters.