The power chosen for a patient of only spherical refractive error
is -0.25D less than the spectacle prescription and if there is a cylindrical component to add half that to the spherical component. Using this, the power of the lens
in the right eye would be -1.75D and around -2.00D for the left. You have to be aware that the vision without a toric component will not be as optimal as spectacles, however.