Capacity (unaided)
≠
Performance (with treatment)
Income-protection policies usually assess treated performance. Discrimination statutes often look at the unmitigated baseline. Mixing those axes is the mitigated-state trap.
Capacity (unaided)
WHO-ICF: what you can do without aids in a standard setting
Performance (with treatment)
WHO-ICF: what you actually do with treatment, aids, and environment
Claim tip
Write both: function without current treatment, and function on the treatment you actually take — including side-effects.