The front-surface power of a spectacle lens is +6.00 D. Its back-surface power values are -8.00 D at the 90-degree meridian and -6.00 D at the 180-degree meridian. The prescription should be written in _ and is exactly _.

A. sph, +6.00 D, -8.00 D, -6.00 D
B. cylinder form, +6.00 D, -8.00 D x 90, -6.00 D x 180
C. prism form, +6.00 D, -8.00 D, -6.00 D
D. axis form, +6.00 D, -8.00 D at 90 degrees, -6.00 D at 180 degrees

Correct option is B) The spectacle lens prescription with a front-surface power of +6.00 D and back-surface powers of -8.00 D at the 90-degree meridian and -6.00 D at the 180-degree meridian should be written in cylinder form as +6.00 D, -8.00 D x 90, -6.00 D x 180.

The prescription for a spectacle lens should be written in cylinder form, as the lens has different powers at different meridians. Therefore, the correct prescription is +6.00 D, -8.00 D x 90, -6.00 D x 180. This notation indicates that the front-surface power of the lens is +6.00 diopters, which is a converging (convex) lens, and there are two back-surface powers for the two meridians at 90 degrees (-8.00 diopters) and 180 degrees (-6.00 diopters), which are diverging (concave) powers. The negative sign before these powers indicates that these are concave lenses that spread light rays outwards.