A: Influence of the apical radius of the corneal surface modeled as a revolution conic on the distance between the BFS to the apex. There is a non linear increase of the distance to the apex (anterior elevation) of the BFS radius with the decrease of the apical radius (apical steepening) of the surface.
B: Influence of the asphericty of the corneal surface modeled as a revolution conic on the distance between the BFS to the apex. There is a non linear increase of the distance to the apex (anterior elevation) of the BFS radius with the increase of negative asphericity (increased prolateness) of the surface.