Wrap frames induce BO prism, so BI prism is needed to compensate. It should be surfaced/generated prism for best effect, but of course simply decentering optical centers can achieve that too. If the PDs on that pair are intentionally narrow to produce BI prism they must be plus lenses. If they are nasally decentered minus lenses, that resultant prism is BO, which just exacerbates the wrap prism.
"The rule of thumb is:
For powers <±2.50D, order with 0.25ΔBI in each eye
For powers >± 2.50D, order with 0.50ΔBI in each eye"
https://www.allentownoptical.com/wra...on-sunglasses/
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