ANY ONE CAN HELP ME ON THIS QUESTION....TQ!


The prescription R +6.00/+2.00x90 at 15mm is to be dispensed at 10mm.
The base curve of the spectacle lens is to be -6.00D and the vertex power allowance -0.80D. The refrative index is 1.50.


Find (i) The presciption at the correct vertex distance.
(ii) The cross curve of the spectacle lens.
(iii) The compensated front surface power.
(iv) The axial thickness


PLS SHOW THE ANSWER AND THE HOLE FORMULA.....TQ