Calculation Form for Diving Masks

For the glazing of our dive masks, the higher BVD (Best Vision Distance) must be taken into account. Our dive masks are calculated based on a BVD of 25mm. Most frame lenses are based on a BVD of 16mm. For calculating the lenses and, consequently, the prices, we use this calculation model.
Image Original Values Calc to + cyl. Calc to BVD=25
Sphere
Cyl.
Axis
Original BVD