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For the weakly coupled heterotic string (WCHS) there is a well-known factor of 20 conflict between the minimum string coupling unification scale, Lambda(H)similar to 5x10(17) GeV, and the projected minimal supersymmetric standard model (MSSM) gauge coupling unification scale, Lambda(U)similar to 2.5x10(16) GeV, assuming an intermediate scale desert (ISD). From a bottom-up approach, renormalization effects of intermediate scale MSSM-charged exotics (ISME), which are endemic to quasirealistic string models, can resolve this issue by pushing the MSSM scale up to the string scale. However, for a generic string model, this implies that the projected Lambda(U) unification under the ISD assumption is accidental. If the true unification scale is Lambda(H)greater than or similar to 5.0x10(17) GeV, is it possible that an illusionary unification at Lambda(U)=2.5x10(17) GeV in the ISD scenario is not accidental? (This is an issue recently raised again by Binetruy et al..) Optical unification suggests that Lambda(U) might not be accidental. Through its ISME constraints, optical unification offers a mechanism whereby a generic MSSM scale Lambda(U)