Am trying to help a disabled adult. He is not in a position to be taken to get new eye exam for new glass prescriptions. His existing prescription is R/E, SPH +1, CYL -1.5, Axis 100, and L/E, SPH -1, CYL -1, Axis 75; and he is indicating that his eyesight seems to be worsening. I want to order 2-3 pairs of glasses for him, with various higher powers....and see what may work for him. Is it sufficient if I just went with stronger SPH in increments of 0.25; or do i need to work with the CYL too? Thanks