Figure 1. Basic parameters while fitting scleral contact lenses: Four basic lens parameters and the corresponding ocular zones while fitting scleral contact lens on the eye.

Zone A indicate central lens vault at the centre of the corneal region (red). Zone B indicate Limbal lens vault within the Limbal region (blue). Zone C indicate mid-haptic region of the lens within the peri-Limbal region (green). Zone D indicate lens haptic and edge resting on the scleral region (yellow).