For the purposes of this Chapter, permanent disablement of a person shall be deemed to have resulted from an accident of the nature referred to in sub-section (1) of section 140 if such person has suffered by reason of the accident, any injury or injuries involving—

1. permanent privation of the sight of either eye or the hearing of either ear, or privation of any member or joint; or
2. destruction or permanent impairing of the powers of any member or joint; or
3. permanent disfiguration of the head or face.