As sagittal depth increases, what happens to vaulting?

As sagittal depth increases, vaulting increases. Sagittal depth refers to the total height of the corneal curvature from a reference plane, typically when fitting contact lenses. When the sagittal depth of a lens increases, it means that the central portion of the lens is elevated more from the surface of the eye, thereby creating a greater vault.

This increase in vaulting is particularly relevant in soft lens fitting where the lens needs to clear the central cornea to avoid contact with the eye and to comfortably fit over the contours of the cornea. If the sagittal depth of the lens is greater, the distance between the back surface of the lens and the cornea increases, hence resulting in more vault.

Understanding this relationship is essential for ensuring optimal lens fit and comfort, as well as for maintaining healthy corneal physiology. Too much vault can cause excessive movement and discomfort, while too little vault can lead to corneal staining or irritation. Therefore, the effect of increasing sagittal depth on vaulting is a key concept in lens fitting practices.