What is defined as the lens location of zero deviation of the optical axis?

The lens location of zero deviation of the optical axis is referred to as the optical center. This point is critical in lens design because it is where light rays passing through the lens do not deviate, or bend. When incoming light travels through the optical center, it continues on its original path without any refractive alteration, which is essential for achieving clear vision with minimal distortion.

Understanding the significance of the optical center is vital for prescribing lenses accurately. If the optical center is misaligned with a person's visual axis, it can lead to visual disturbances and discomfort. This concept underlies the importance of proper fitting in lens prescriptions.

In contrast, the focal point indicates where parallel rays of light converge after passing through the lens, vertex distance relates to the distance between the back surface of the lens and the cornea, and the optical zone refers to the area of the lens that provides clear vision. These terms serve different functions in optical science, but the optical center specifically defines a position of no light deviation.