Sentence:  It seems clear , when one takes into consideration the exceedingly defective eyesight of the patient ( we shall describe it in detail in connection with our second question , the one concerning the psychical blindness of the patient ) , that he had to rely on his <WSD>sense</WSD> of touch much more than the usual portfolio maker and that consequently that faculty was most probably more sensitive to shape and size than that of a person with normal vision . 
Meaning of the word marked with <WSD> tags:  the faculty by which external objects or forces are perceived through contact with the body (especially the hands)