No person shall [have the right to vote, or] be eligible to office under the constitution of this commonwealth, who shall not be able to read the constitution in the English language, and write his name: — provided, however, that the provisions of this amendment shall not apply to any person prevented by a physical disability from complying with its requisitions, nor to any person who now has the right to vote, nor to any persons who shall be sixty years of age or upwards at the time this amendment shall take effect. [See Amendments, Arts. III, XXIII, XXVI, XXVIII, XXX, XXXI, XXXII, XL, XLV and LXXVI.]