i just bought a pair of polarized prescription sunglasses. When i wear them and look at my monitor i can black spots on the outer edge of the lenses. Is this normal or is it cause of a cheap polarization?

it's normal, mostly prescription polarized lenses meet this issue. Never mind.

Because the polarizing stripes reduce the amount of light entering the eye, polarized lenses cannot be used for regular eyewear with clear lenses.