Barry's client is experiencing 3.5 prism diopters (-5.00 x .7cm) on the primary gaze, or on axis.
The LCA is 3.5Δ/30 = .12Δ.
Not significant, but not voodoo or pseudoscience- the vision and comfort suffers, especially when combined with the other errors.
Unlike some technical articles I've read in the trades, this piece is filled with useful information and is top-down, dead on balls accurate.
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